Heater Fireman's Switch Control Question

[rscam]

I'm installing a new Raypak Digital 336A heater and am looking to do a simple control using an intermatic timer and a "Fireman's Switch" (see product attached). Raypak's manual offers 2 options for dry contact control of the heater. I can wire to their "Fireman's switch " circuit or to their "Remote" circuit. Seems like both ways will achieve the same result with some subtle differences. Just wondering if their might be some pros and cons to doing it one way vs the other?

For background a simple control where I could have the heater kick on early in the morning on days when I know we'll be entertaining etc is all I need. 75 % of my season the heater will not be in use. I only have a pool, no spa.

Thanks

 

[ajw22]

Connect to the Firemans Switch as described...

https://s3.amazonaws.com/AWSProd/sites/raypakcom/documents/241236.pdf

 

[rscam]

Thanks AJ. I guess it was a silly question. Using as manufacturer intended is smart approach.

 

[1poolman1]

I'm installing a new Raypak Digital 336A heater and am looking to do a simple control using an intermatic timer and a "Fireman's Switch" (see product attached). Raypak's manual offers 2 options for dry contact control of the heater. I can wire to their "Fireman's switch " circuit or to their "Remote" circuit. Seems like both ways will achieve the same result with some subtle differences. Just wondering if their might be some pros and cons to doing it one way vs the other?

For background a simple control where I could have the heater kick on early in the morning on days when I know we'll be entertaining etc is all I need. 75 % of my season the heater will not be in use. I only have a pool, no spa.

Thanks

All the fireman's switch you have referenced does is turn the heater off about 20 minutes before an Intermatic T10XX turns the pump off if that is how your pump is wired. With a VSP, it shouldn't be.
They were used to cool down older heaters that retained so much heat that without a cool down turning the pump off without it would melt the PVC plumbing. New heaters don't require them as they don't retain that much heat. It will not turn your heater on. If the heater is powered by the timer it will turn power on and off with the timer and that switch is not needed. It will heat if there is a call for heat and waterflow.

 

[ajw22]

All the fireman's switch you have referenced does is turn the heater off about 20 minutes before an Intermatic T10XX turns the pump off if that is how your pump is wired. With a VSP, it shouldn't be.

The Fireman's Switch will cycle the heater On and OFF. What I read is @rscam wants to run the heater for a time period set on the timer while the VSP runs longer.

The heater stays ON with the temperature set to whatever is desired and the timer connected to the Firemans Switch cycles the heater daily on the timer schedule.

 

[1poolman1]

The Fireman's Switch will cycle the heater On and OFF. What I read is @rscam wants to run the heater for a time period set on the timer while the VSP runs longer.

The heater stays ON with the temperature set to whatever is desired and the timer connected to the Firemans Switch cycles the heater daily on the timer schedule.

So then, there is no need for a true fireman's switch which was designed to do what I described, turn the heater off 20 minutes +/- before the the single-speed pump was turn off by the time clock.

That switch is just a micro-switch with the NO terminal removed. When the cam that is mounted behind the "off" tripper on an Intermatic clock hits the switch it opens the NC contacts, interrupted the control voltage (mV or 24V) and let the pump run to cool the heater. Pump then turned off. Usually the power to the heater was cut at the same time. Once the cam has passed the "off" time, the contacts would close, but unless there is power to the heater and the proper waterflow it will not fire. Switch can't turn it on, only off

Since his pump is not/won't be controlled with that timer, the fireman's switch is not needed. If the timeclock motor was to be wired separately from the 1& 2 terminals on a T101, wire a loop from the circuit board "fireman's switch" terminals to them, and the clock would then act as a dry relay to complete the control circuit. No need to purchase that switch.

 

[ajw22]

If the timeclock motor was to be wired separately from the 1& 2 terminals on a T101, wire a loop from the circuit board "fireman's switch" terminals to them, and the clock would then act as a dry relay to complete the control circuit. No need to purchase that switch.

Yeah, that is what I was thinking all along.

Not the Intermatic 156T4042A Heater Control Switch Kit that shuts down the heater when the timer is controlling the pump.

We were talking about two different things on the Intematic timer.

Timers - Further Reading

www.troublefreepool.com

 

[rscam]

Poolman and AJW, Thanks so much for the help. I assumed that the Fireman's switch that I bought operated like this: when the "on" cam passed it would close the contact and then when the "off" cam passed it would open the contact. I would provide continuous power to the heater, leave the heater on and set to the desired temp and then rely on the firemans switch to turn on and off like above. Sounds to me from your comments that the switch I bought will only open the contact and not close it.

For a little more background. I currently control the pump with its onboard timer controls. I use the old school intermatic timer to power my swg on and off when I know pump will be running as a safety measure so I don't just rely on the flow switch.

My goal was to piggy back on the timer somehow to also control the heater. I didn't think it was good practice to kill and resume the power to the heater using the time clock so I thought that a dry contact approach connected to the heaters Fireman's switch circuit (or it's "remote" circuit) would be the way to go. I won't run the heater everyday. I'm mainly doing this to use sporadically throughout the season for days when I know we are entertaining and I want the heater to kick on when the pump comes on (very early) so it has time to heat the pool up. Otherwise I'll have to wake up early enough to turn it on manually which is not ideal.

From your comments it seems like there is still a way to do what I want but I'm a bit confused about this:

If the timeclock motor was to be wired separately from the 1& 2 terminals on a T101, wire a loop from the circuit board "fireman's switch" terminals to them, and the clock would then act as a dry relay to complete the control circuit

Isn't the timeclock circuit a "powered" circuit? How will it act as a dry relay? I think I'm missing something?

 

[1poolman1]

Poolman and AJW, Thanks so much for the help. I assumed that the Fireman's switch that I bought operated like this: when the "on" cam passed it would close the contact and then when the "off" cam passed it would open the contact. I would provide continuous power to the heater, leave the heater on and set to the desired temp and then rely on the firemans switch to turn on and off like above. Sounds to me from your comments that the switch I bought will only open the contact and not close it.

For a little more background. I currently control the pump with its onboard timer controls. I use the old school intermatic timer to power my swg on and off when I know pump will be running as a safety measure so I don't just rely on the flow switch.

My goal was to piggy back on the timer somehow to also control the heater. I didn't think it was good practice to kill and resume the power to the heater using the time clock so I thought that a dry contact approach connected to the heaters Fireman's switch circuit (or it's "remote" circuit) would be the way to go. I won't run the heater everyday. I'm mainly doing this to use sporadically throughout the season for days when I know we are entertaining and I want the heater to kick on when the pump comes on (very early) so it has time to heat the pool up. Otherwise I'll have to wake up early enough to turn it on manually which is not ideal.

From your comments it seems like there is still a way to do what I want but I'm a bit confused about this:



Isn't the timeclock circuit a "powered" circuit? How will it act as a dry relay? I think I'm missing something?

That Intermatic switch is always "on (closed)." It is a normally-closed switch as the normally-open terminal of a standard micro switch has been removed. It is designed to turn the heater off for about 20 minutes before a pump is turned off.

There is one cam and it is mounted behind the "off" tripper on an Intermatic time clock. It won't do anything else. It only interrupts the control circuit to get the heater to stop. The switch only stays "off" for as long as it takes the cam to pass by.

If you remove the small white motor wires from the terminals of an Intermatic and hook power directly to them the clock will run, the dial will turn. If there are trippers on the dial it will connect terminals 1 & 2 on a T101 when the "on" tripper passes the indicator and disconnect them when the "off" tripper passes it. If you use a T104 (240V) it will connect 1 &2 and 3 & 4. Hook the heater control wires from the location in the heater to 1 & 2 (or 3 & 4) and it will complete the circuit allowing the heater to fire when the "on" tripper passes the indicator and closes those contacts, and will stop the heater when the "off" tripper passes and opens them.

If you want, you can skip the above, leave the heater switch in the "on" position, set a temperature, and use the Intermatic to just turn power to the heater on and off at your schedule and accomplish what you want to do. Since the 336A does not have a blower that needs to run after the the heater stops heating, you can power cycle it with no problem, its still done regularly with systems that don't have automation and the the heater is powered along with the old single or two-speed pump. Still no need to purchase the Intermatic fireman's switch as it won't do that.

 

[ajw22]

Poolman and AJW, Thanks so much for the help. I assumed that the Fireman's switch that I bought operated like this: when the "on" cam passed it would close the contact and then when the "off" cam passed it would open the contact. I would provide continuous power to the heater, leave the heater on and set to the desired temp and then rely on the firemans switch to turn on and off like above. Sounds to me from your comments that the switch I bought will only open the contact and not close it.

I see the confusion now. I never looked at the pic you attached and assumed you were talking about using an Intermatic timer and not that Fireman's switch add on.

I didn't think it was good practice to kill and resume the power to the heater using the time clock so I thought that a dry contact approach connected to the heaters Fireman's switch circuit (or it's "remote" circuit) would be the way to go.

You are correct.

I won't run the heater everyday. I'm mainly doing this to use sporadically throughout the season for days when I know we are entertaining and I want the heater to kick on when the pump comes on (very early) so it has time to heat the pool up. Otherwise I'll have to wake up early enough to turn it on manually which is not ideal.

You will have to manually turn the heater ON and OFF before and after an entertaining day since the timer will try and turn the heater on every day.

Isn't the timeclock circuit a "powered" circuit? How will it act as a dry relay? I think I'm missing something?

The Intermatic timer needs power to run its clock motor. When the timer is powering a device like a pump or SWG you can use the same power line to power the timer clock.

For switching the heater Fireman's Switch using the timer relay, not the add on gadget, which has no power you have to provide independent power to the clock motor for the timer to run. This assumes you are using a standalone timer for your heater which I incorrectly assumed.