GFCI overheating

[JamesW]

Is the breaker arc fault as well as ground fault?

When the contacts for the heater close, the high amperage can and will cause arcing, which can trip an arc fault breaker.

If the breaker is arc fault and an arc fault breaker is not required by code, you might want to replace the breaker with a non arc fault model.

The breaker specified is 60 amp GFCI, so that is what should be used.

The Romex is only rated to 55 amps, so it is too small for a 60 amp breaker.

What is the make and model of the breaker?

Expected heat rise in normal applications.

This section discusses the expected temperature rise we encounter on the cover of the panel or the handle of the circuit breaker.

The line terminal or bus bars, as called out above, will not be discussed.

A panel full of non-electronic, standard thermal-magnetic circuit breakers running a heavy load—for instance, above 50% the rating for the main circuit breaker protecting the panel, or 100 A in a 200 A service—is expected to rise 15 °C (27 °F) above ambient temperature.

Eaton AFCI circuit breakers consume less than 1 watt to power up the electronics within the breaker. This additional power consumption, above the contribution from the mechanical components mentioned above, can add another 5–10 °C (9–18 °F) of heat rise above ambient for the system.

Eaton AF/GF circuit breakers consume slightly more than 1 watt to power up their internal electronic components. A panel full of AF/GF breakers might rise 10–20 °C (18–36 °F) above ambient.

Given a typical mix of circuit breakers and typical consumption, we expect a 25–30 °C (40–54 °F) heat rise on the hottest part of the exposed panel cover above the ambient temperature.

In a 38 °C (100 °F) garage, it would not be surprising, nor would it be unsafe, to see a panel as warm as 65 °C (150 °F).

As demonstrated above, the materials of the circuit breakers are designed and tested to function in much higher temperatures than 65 °C (150 °F).

https://www.eaton.com/content/dam/eaton/products/low-voltage-power-distribution-controls-systems/circuit-breakers/eaton-circuit-breakrs-meet-or-exceed-the-strict-requirements-for-the-heat-rise-from-underwriters-laboratories-ap003001en.pdf

 

[JamesW]

Understanding acceptable circuit breaker operating temperatures will help avoid unnecessary replacements and returns.

A circuit breaker that is warm to the touch, or too hot to touch, is normally within acceptable operating temperatures.

Therefore, it is important to obtain the temperature reading on the circuit breaker rather than going by touch.

Non-metallic handles, knobs, and other user contact surfaces are allowed to reach a maximum temperature of 185ºF (85ºC) per Underwriters Laboratories® (UL®).

Acceptable Operating Temperatures are Defined by UL 489

The acceptable operating temperature of a circuit breaker is defined by UL in the UL489 Standard (reference Jan. 2013), which is summarized in the table below.

Summary of Allowable Temperature Rise and Maximums for a Standard Rated Circuit Breaker

NOTE: Circuit breakers are usually calibrated for 104ºF (40ºC) ambient.

Terminations for standard rated circuit breakers: Paragraph 7.1.4.2.2 says the temperature rise on a wiring terminal at a point to which the insulation of a wire is brought up as in actual service shall not exceed 90ºF (50ºC).

Terminations for 100% rated circuit breakers: Paragraph 7.1.4.3.3 says the temperature rise on the termination service shall not exceed 108ºF (60ºC).

Handles, knobs, and other user surfaces: Paragraph 7.1.4.1.6 says the maximum temperature on handles, knobs, and other surfaces subject to user contact during normal operation shall not exceed 140ºF (60ºC) on metallic and 185ºF (85ºC) on nonmetallic surfaces.

https://www.productinfo.schneider-electric.com/0600db1603cboptemps/0600db1603-circuit-breaker-operating-temperatures/0600DB1603%20Circuit%20Breaker%20Operating%20Temperatures/English/0600DB1603%20Circuit%20Breaker%20Operating%20Temperatures_0000362832.xml/$/Introduction-98EEE9A4

https://ckm-content.se.com/ckmContent/sfc/servlet.shepherd/document/download/0691H00000EEIbgQAH

 

[JamesW]

What is the power rating of the heater?

How many pumps do you have and what is the amp rating of each pump?

 

[KyMama]

So, after reading all that and not understanding most of it I'm thinking my best bet is to call the electrician and have them come out and check everything for me. Not only would it probably be safer but I think it will be quicker because they will know what the readings mean without me having to come back here and us having to go back and forth. I will ask them for all the information and come back to let y'all know what's going on and what they recommend as a fix.

Thanks again.

 

[JamesW]

Note: Breakers rated 100A or Less must be sized using the 60°C column of Table 310.15(B)(16) UNLESS marked for use with 75 deg. wire.

You have to check the terminal rating temperature of the breaker to see if it is rated for 60°C or 75°C.

For example, if you replace the supply line with #6 THHN, which is rated to 90° C, you cannot use the 90°C ampacity (75 amps), you have to use the 60°C ampacity (55 amps) unless the breaker is rated for 75° C terminals and you can use the 75°C ampacity (65 amps).

If you use Romex NM-B or a breaker with 60°C terminals, you have to use the 60°C ampacity, which would require #4 AWG Romex or #4 AWG THHN.

It seems that the 90 degree C rating for wire ampacity is not going to be useable in most cases due to the terminal lug ratings on circuit breakers.

Even if the breaker terminals are rated for 90 degrees C, you would still use the 75 degrees C or the 60 degrees C rating depending on the wire type.

So, even if you go with THHN wire, you would have to use the 60 degree C or 75 degree C rating depending on the terminal rating.

What is the temperature rating of the lugs on circuit breakers?

Are breakers rated for 90C wire?

The wire temperature rating allowed for use in circuit breakers lugs is 75°C.

While it is acceptable to use 90°C wire, that 90°C wire must be sized as if it is 75°C wire.

This is according to the UL standard for circuit breakers, which is summarized as follows:

(1) Breakers rated 125 A or less must be marked for use with 60°C, 60/75°C, or 75°C only wire.

(2) For breakers rated more than 125 A, the proper wire temperature rating is 75°C and the marking is optional.

(3) Wire with a higher temperature rating can be used (e.g. 90°C), but the ampacity of the wire must be based on the wire temperature marked on the breaker.

Therefore, as marked on the breaker, the wire must be sized as 75°C wire. Even when using 90°C wire, the wire must be sized as if it is 75°C wire.

What is the temperature rating of the lugs on circuit breakers? | Schneider Electric USA

 

[JamesW]

What are the NEC rules for sizing conductors terminated on a circuit breaker?

How to determine what size wire should be used on a circuit breaker

Molded Case Circuit Breakers

Per NEC 110.14(C)(1):

Conductors must be sized based on the 60 deg. C or 75 deg. C column of Table 310.15(B)(16) that corresponds to the terminal rating of the circuit breaker.

(a) Equipment rated 100 A or less must be sized using the 60°C column of Table 310.15(B)(16) UNLESS marked for use with 75 deg. wire, in which case the 75 deg. column is used.

(b) Equipment rated over 100 A must be sized using the 75°C column of Table 310.15(B)(16).

Wire with higher insulation temperatures can be used provided it is sized appropriately per NEC rules summarized above.

Schneider Electric typically marks circuit breakers with terminal (conductor) temperature ratings only on frame sizes with ampacities of 100 A or less.

Circuit breakers rated over 100 A are required to be terminated with conductors rated at least 75 deg. C and so are not typically marked with the temperature rating.

What are the NEC rules for sizing conductors terminated on a circuit breaker? | Schneider Electric USA

www.se.com

Terminal Ratings

75 °C vs. 90 °C Terminal Rating.

Terminals are marked to indicate the maximum wire temperature rating that is approved for use.

In relation to molded case circuit breaker application, the temperature rating is typically 90 °C or 75 °C.

Although the terminal is marked with applicable wire temperature rating, it is important to note UL 489, the standard to which MCCBs adhere, only recognizes 60 °C and 75 °C wire for testing purposes and rated use.

If 90 °C wire is used to connect to an MCCB, the wire must be applied at its 75 °C rated ampacity.

As an example, 90 °C wire is often required for use in 100% continuous current rated MCCB applications.

When this is the case, the 90 °C wire must be applied at its 75 °C rated ampacity, which often results in the wire being selected one size larger than typical.

An example of the terminal markings and corresponding designations is on Page V4-T2-117

https://www.eaton.com/content/dam/eaton/products/electrical-circuit-protection/molded-case-circuit-breakers/mccb-catalog-v4-t2-ca08100005e.pdf

 

[JamesW]

 

[RDspaguy]

The temperature of the breaker indicates it is getting a sustained overload causing thermal trips.

A clamp on amp meter should be put on the circuit to monitor the load during the spa operation.

@RDspaguy may have thoughts.

Breaker tripping after adding Aquarite SWG

Hello all! This place has been a great resource in the past, and I'm hoping for some more advice regarding electrical wiring. I'm posting mostly to get a second opinion and make sure my thinking is correct and that I'm not missing any obvious options or things to check. Last summer I had no...

www.troublefreepool.com

The tub manual specifies a 60 amp breaker, which means that the wire also has to be rated to at least 60 amps.

The Romex NM-B 6 AWG is only rated to 55 amps, which means that it is too small.

The correct NM-B Romex would be #4 AWG.

In my opinion, the wire and breaker need to be redone to meet the specifications.

I think @JamesW Summed it up quite well. Repeatedly. With links and charts.
The control system may be convertible, and can be made to work with a lower amp draw by regulating what can run when. Post pics of the circuit board and wiring diagram so I can see what you've got.

 

[JamesW]

A breaker should hold at it's full rated capacity.

So, even if the load is 50 amps, the breaker should not trip.

A 60 amp breaker should not exceed 48 amps by design (80%).

So, since the required breaker is 60 amps, the expected tub load should not exceed 48 amps and a 50 amp breaker should not be overloaded.

The wire is rated to 55 amps, so it should carry the tub load, which should not exceed 48 amps.

The breaker is tripping and the specified required trip is at 135% of the rated capacity, which is 67.5 amps.

If the problem is an overload, then the current is likely to be between 51 amps and 67.5 amps, which would point to a problem other than the wire or breaker.

We really need to know the amp draw at full load on each hot leg and the neutral and the voltage with no-load and with a full load hot-to-hot and each hot to neutral.

Until we get that information, we are just speculating.

Maybe the wiring is incorrect.

Replacing the wire and breaker are necessary in my opinion and that might solve the problem, but it seems to me that there might be another issue as well because even though the wire and breaker are undersized, I think that they should still carry a load up to 48 amps.

If the current is over 48 amps, that points to a problem with the tub.

If the voltage drop is more than 3%, that points to a wiring issue.

If the voltage with no load is outside of normal limits (High or Low), that points to a voltage supply issue.

In any case, we still don’t know why the breaker is getting hot, if it is too hot and we don’t know why the breaker is tripping.

It might be tripping due to arc-fault, ground fault, a bad breaker, bad wire connections, overload, short, undersized wires, undersized breaker, breaker overheating from an external heat source or some other reason or several reasons combined together.

The available information is insufficient to allow us to make a diagnosis with any certainty.

 

[RDspaguy]

Many newer tubs need 60 amps to run all pumps and heater simultaneously, and pushing the limits of a breaker can cause it to get hot and trip. A tub pulling 48 amps won't immediately trip a 50 amp breaker, but can get it hot over time. Once it starts tripping you're getting arcing and therefore damage to the contacts and therefore more heat. It's a decending spiral of breaker doom.
In most cases, a dipswitch or jumper pin on the board determines the set-up. Once the heater is turning off with the jets on you're down in the 40 amp zone usually.
So post a pic of the board and diagram so I can see if that's a possibility. It may save you from replacing anything in under a minute.

 

[JamesW]

If there is a breaker in the garage and one outside and if they are both 50 amp breakers, why is the one in the garage not tripping when the one outside is?

The electrician should verify which size breaker is in the garage.

Maybe it is a 60 amp?

The electrician should also add up all electrical components to see what the maximum amp draw is.

The heater is a 5.5kW Heater, which is about 23 amps at 240 volts.

The Total Horsepower for the jets is rated at 12 HP, which is probably about 24 amps.

12 hp is 8,952 watts at 746 watts per hp.

8,952 watts is 37.3 amps at 240 volts, so the rated HP is not likely as shown below where the 6 hp is 12 amps or 24 amps for two.

So, the total amperage with both jet pumps on and the heater is likely to be 47 amps and then a little bit extra for ozone and lights.

To make the current setup work, you would have to disable the heater when the jets are on or one of the jet pumps when the heater is on.

If you can do that with a setting, that might be a solution.

If the heater is turned off while both jet pumps are on then the water might cool off too much if you are in for a while.

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[KyMama]

Just to clarify something real quick, when the breaker is kicking I am only calling for heat. Obviously, this means the heater, a pump and I assume the ozonator are running. No lights, no jet 2 and no speakers because we don't have them. I don't know if that makes a difference but wanted to make sure everyone was aware. It took two days but I was finally able to get the temp back up to 100 degrees. I only asked for 2 degrees at a time and every hour and a half I would go ask again. This seemed to be the magic number to keep it from tripping and give it time to cool back down. May not have been the safest thing to do but I wanted to make sure it was warm enough to not have to worry about it everyday in case it gets cold again and the breaker trips without me knowing - I'm afraid it will freeze and us not realize.

Both breakers are 50 amp. I believe someone asked about whether or not the wires were getting hot. I checked that and neither the wire coming from the tub to the spa panel nor the wire from the spa panel to the main panel are getting hot, they aren't even warm.

I called my electrician and they are gonna come out this week and check everything for me. I will ask them for the following information, "We really need to know the amp draw at full load on each hot leg and the neutral and the voltage with no-load and with a full load hot-to-hot and each hot to neutral." and get back with you. Or if you have specific questions I can print and ask them please let me know. I'm assuming it will be at least Tuesday before the get out here because of the holiday so I got a day or so to gather questions.

Thanks!

 

[JamesW]

Just to clarify something real quick, when the breaker is kicking I am only calling for heat.

With just the heater, the amperage should be about 24 amps for the heater and maybe a few amps for the circulation pump, ozonator and controls.

This should not trip the breaker.

Water Capacity = 370 gallons x 8.34 = 3,086 lbs

5.5 Kilowatts (kW) = 18,767 Btu/hr

18,767/3,086 = 6.1 degrees per hour.

If the water fill is 54 degrees and you want to get to 104 degrees, then it will take 8.2 hours to rise by 50 degrees Fahrenheit.

That’s 24 amps at 230 volts for about 8 hours.

People don’t get in the tub until the water reaches temperature.

So, they might get in for 1 hour with both jet pumps on and the heater is also on for a total of 48 amps for 1 hour.

The ozonators, lights and controls might add another 2 amps, which gets us to 50 amps, which is the rating of the breaker.

A breaker should be able to handle a full rated load for 1 hour unless there is some reason that it is in an enclosure that is getting excessively hot. This assumes that no load was on for more than 3 hours.

For example, if the heater is on for 1 hour to heat up and then the jet pumps plus the heater are on for 1 hour while people are in the tub, the loads are noncontinuous and the breaker should hold for the hour assuming a load of 50 amps or less.

Note: The breaker should be able to handle 125% of the continuous load (any load on for 3 hours or more) plus 100% of the noncontinuous load.

The breaker rating is at 104 degrees Fahrenheit.

If the breaker is exposed to higher temperatures, the breaker has to be derated according to the manufacturer's temperature derating chart.

For example, a breaker exposed to 122 degrees F might need to be derated to 48 amps and a breaker exposed to 140 degrees F might need to be derated to 45 amps.

 

[JamesW]

In my opinion, the original electrician made a mistake and they should be liable to replace the wiring and breaker.

This falls under “Errors and Omissions” liability, which some people have insurance for.

In any case, they should redo the installation for no cost.

Here are the questions I would want to know the answers to.

1) What wire size from the outside breaker to the tub?

2) What is the amperage on both hot legs and the neutral when heating with no jet pumps and with heat and jet pumps?

The amperage on both hot legs should be close and the amperage on the neutral should be low and it should be the difference from one hot leg to the other hot leg.

3) What is the voltage at the tub with no load, with heater only and then with heater and both jets?

Measure hot to hot and from each hot to neutral.

For example, the no-load voltage might be 240 volts and the voltage under load might go down to 233 volts, which is a voltage drop of 7 volts, which is the maximum voltage drop to limit the voltage drop to less than 3%.

Note that the voltage will always go down some (voltage drop) when you add a load to the line. The larger the load, the higher the voltage drop. Excessive voltage drop points to a wiring issue.

4) Is there any sign of a ground fault?

5) Is the outside breaker GFCI and Arc-fault or just GFCI?

Note: Arc-fault is highly unlikely on this type of breaker. Most likely, the breaker is only GFCI. I'm not even sure if they make a 50 amp double pole AFCI breaker, at least not in a commonly available breaker.

6) Is there any reason that the breaker is being exposed to excessive heat?

7) What is the total amperage of all equipment from the equipment labels?

 

[JamesW]

If we consider the heater, circulation pump and ozonator to be a continuous load (Estimated at 28.8 amps for more than 3 hours) and the jets (Estimated at 24 amps) to be noncontinuous loads (On for less than 3 hours), then the breaker needs to be rated to (28.8 amps x 1.25) = 36 + 24 amps = 60 amps.

In any case, the manual says to use a 60 amp breaker, so that is a requirement.

The fact that the breaker is tripping with just the heater suggests that the breaker is not overloaded assuming the heater, circulation pump and ozonator are drawing only 28.8 amps.

However, we need to measure the amp draw to be sure.

Can you show the labels of all pumps and the ozonator where the labels show the amps?

If the breaker is getting too hot and tripping at less than 40 amps, then there is a non-overload issue, which might be a bad connection or maybe some other reason for the trip like ground fault or maybe excessive temperatures in the enclosure.

Maybe you can put a thermometer in the enclosure to see how hot it is getting in there?

Only do this if you can do it safely.

Breakers are calibrated at 104 degrees Fahrenheit, so you would want to see if the enclosure is getting hotter than 104 degrees Fahrenheit (40°C).

Breakers in temperatures hotter than 104 degrees need to be derated.

Molded-Case Circuit Breakers & Enclosures.

Eaton thermal-magnetic breakers are calibrated for an ambient temperature 40 °C (104 °F) that is the average temperature within an enclosure; thus, they minimize the need for derating.

If the enclosure ambient is known to exceed 40 °C, the breaker used should either be especially calibrated for that ambient, or be derated accordingly.

In accordance with the National Electrical Code, all circuit breakers are derated to 80% for continuous loads except electronic trip unit circuit breakers that have been tested and marked for 100% application.

https://www.eaton.com/content/dam/eaton/products/electrical-circuit-protection/molded-case-circuit-breakers/consulting-application-guide-molded-case-circuit-breakers-tb01200003e.pdf

The 2011 National Electric Code Section 210.20(A) of the code basically says that a circuit breaker for a branch circuit must be rated such that it can handle the noncontinuous load plus 125% of the continuous load.

A continuous load is one where the maximum current is expected to continue for 3 hours or more.

In other words, the breaker needs an extra 25% capacity of the continuous load for headroom.

That, of course, means you need a larger, more expensive breaker.

https://blog.se.com/datacenter/architecture/2014/06/12/clearing-confusion-80-vs-100-rated-circuit-breakers/

NEC 210.20(A) Continuous and Noncontinuous Loads

Where a branch circuit supplies continuous loads or any combination of continuous and noncontinuous loads, the rating of the overcurrent device shall not be less than the noncontinuous load plus 125 percent of the continuous load.

Exception: Where the assembly, including the overcurrent devices protecting the branch circuit(s), is listed for operation at 100 percent of its rating, the ampere rating of the overcurrent device shall be permitted to be not less than the sum of the continuous load plus the noncontinuous load.

https://www.productinfo.schneider-electric.com/na-std-ref/5c0fee4b347bdf0001de4d55/Conductor%20Ampacity%20Tables/English/Data%20Bulletin%20-%20Conductor%20Ampacity%20Tables%20(bookmap)_0000264293.ditamap/$/NECInformationOfNote-F20BDBCC

What is the difference between a 80% rated breaker and a 100% rated breaker?

Product Line: Molded case circuit breakers.

For a particular breaker, even though the 80% and 100% versions have the same amp rating (use the same trip curve), in actual use they are applied differently depending on the continuous loads (amount and length of time).

The 80% (standard-rated) breaker can only be applied continuously (defined as 3 hours or more by the NEC) at 80% of its continuous current rating.

100% rated circuit breakers can be applied at up to 100% of their current rating continuously.

Breakers rated at 80% can be applied at 100% of their rating if the loading will last for less than 3 hours.

What is the difference between a 80% rated breaker and a 100% rated breaker? | Schneider Electric USA

 

[JamesW]

When we bought the spa we had our main panel upgraded and the electrician installed a separate breaker in the main panel for the spa as well as the outdoor panel.

According to our infrared thermometer the breaker itself is getting to temperatures of at least 140, it is definitely too hot to touch.

Both breakers are 50 amp.

I believe someone asked about whether or not the wires were getting hot. I checked that and neither the wire coming from the tub to the spa panel nor the wire from the spa panel to the main panel are getting hot, they aren't even warm.

If both breakers are the same size and getting the same current (Amperage), you would expect them to get to about the same temperature.

Is the breaker in the garage getting as hot as the breaker outside?

If the breaker is tripping while the jet pumps are off, the load should be under 40 amps (A continuous load estimated at 28.8 amps for more than 3 hours) and the breaker should not be overloaded.

Also, for an overload, the wires would get noticeably warm.

If the garage breaker is not getting hot, then it would point to something other than an overload like a ground fault, hot enclosure or maybe a bad connection on the wire terminals.

What is the normal tub heating time from cold to full temp?

What is the cold temperature and what is the hot temperature?

For example, if cold is 86 degrees and hot is 104 degrees, that is 18 degrees for temp rise and it should take about 3 hours at 6 degrees per hour assuming no heat loss.

 

[JamesW]

Note that it is important to measure the current on both hot wires and the neutral to check for any imbalance.

Most electricians will clamp one leg to measure the amperage and assume that the other leg will be the same.

This is true for a 240 volt appliance, but when you have a mixed voltage setup, the 120 volts will only load one leg.

If you have 120 volt loads, the current on each hot leg will be different unless the 120 volt loads are exactly equal on each leg.

For example, if the 240 volt load pulls 24 amps, then that is 24 amps on both hot legs.

However, if you have a 120 volt load that pulls 5 amps, it will only load one hot leg and it will also put 5 amps on the neutral.

So, you would have 29 amps on one leg, 24 amps on the other leg and 5 amps on the neutral.

The 50 amp double pole breaker is basically two 50 amp single pole breakers tied together.

So, it is the leg with the highest amperage that is going to trip the breaker when you have a mixed 120/240 loading.

You might have one leg at 48 amps and one at 53 amps and 5 amps on the neutral.

The heater and jet pumps should be 240 volts and about 24 amps for each for a total of 48 amps.

At this point, we don’t know what the 120 total amp load is or what equipment is 120 volts.

There should be a circulation pump, ozonators, lights and controls.

The manual shows that a large neutral is required, but we don’t know the expected neutral load.

The total 120 volt load should be pretty low as there is not much room left after accounting for the 240 volt loads.

The specified 60 amp breaker implies an expected maximum load of 28.8 continuous (Heater, circulation pump, ozonator and controls) and 24 noncontinuous (jet pumps) (52.8 maximum) or about 48 amps of continuous load.

The heater and circulation pump have to be considered to be continuous because they can be expected to be on for more than 3 hours.

Check the equipment labels for the amperage of each piece of equipment or just post a picture of the label of each piece of equipment so we can see what the expected draw is.

In the below example, the motor label says 230 volts and it is a 2 speed motor (3,450 RPM or 1,725 RPM) and the amperage is 12 amps at 3,450 RPM or 2.2 amps at 1,725 RPM.

It is also important to check the voltage hot to hot and each hot to neutral with no load and with a full load.

The hot to hot with no load should be about 240 volts and about 233 to 235 with a full load.

The voltage between each hot and neutral should be almost exactly half of the voltage between hot to hot.

The voltage between each hot and neutral should be almost exactly the same.

 

[Randrx2]

It does look like it may be overloaded based on all the posts on this thread (honestly, I skimmed most of posts). However, have you checked for loose connections at the breaker? The wires going into the breaker may be loose (turn off power and tighten) or the breaker contacts to panel stabs may be loose (replace breaker).

 

[JamesW]

It does look like it may be overloaded based on all the posts on this thread (honestly, I skimmed most of posts). However, have you checked for loose connections at the breaker? The wires going into the breaker may be loose (turn off power and tighten) or the breaker contacts to panel stabs may be loose (replace breaker).

We did have the gfci breaker replaced early into the problem in case it was just a bad breaker.

The breaker was replaced, so that should have resolved any loose connections, but it's still possible that the connections are bad.

The breaker is tripping at less than full load, so it seems like it's more than just and overload.

The temperature of the breaker seems excessive, which points to an overload, but we really need to know some measurements to know where the likely problem is.

The electrician should check for any type of ground fault as there might be some reason that it is an intermittent ground fault issue.

Pictures of everything would be helpful in case it is something obvious.

 

[JamesW]

In my opinion, we know for sure that the breaker and wire are undersized from the manual specifications that say to use a 60 amp breaker and the breaker is only 50 amps and the wire is only rated to 55 amps.

Replacing the wire and breaker should be done for no cost by the original electrician because it is their mistake, but they might not be available and the customer might not want the incompetent person to come back to do any work.

I would have the new electrician redo the wiring and breaker and send the bill to the original electrician.

Replacing the wire and breaker might fix the problem but it might not if there is a different issue.

A competent electrician should be able to accurately diagnose the problem and recommend a proper solution.