Minimax Heater Issue

[TAH]

Hi,

I have a Purex Triton (Pentair) MiniMax 400 heater. It has worked perfectly for many years but upon opening the pool this year it failed to light. None of the LEDs is lighting up so I'm assuming it's a power issue. The transformer appears somewhat corroded but more importantly, what I assume is the circuit breaker, which is mounted to the outside of it, appears to be popped and won't reset. I say appears because I've actually never seen a circuit breaker like it before. It's a small, round black button that is spring loaded. I can push it in but it doesn't stay in and there's no resistance (other than the spring) or "clicking in." When I looked on the web for the part (assuming that was the issue), it shows as obsolete or discontinued on several sites. For example, one site's parts diagram says "Minimax Transformer, 1384c - Dual Voltage; Note: Circuit Breaker is No Longer Available."

I am obviously not an electrician but am I likely correct that the problem lies in the transformer, causing the circuit breaker to pop? And if so, do I simply buy the replacement transformer without the circuit breaker?

Thanks!

Tom

 

[CraigMW]

I'm not suggesting this as a permanent solution, but if you bypass the circuit breaker, does this fix the problem (i.e. if you run the power directly to the transformer)? You could test this using a test lead with alligator clips. Just bypass the breaker by attaching the lead between the terminals for the breaker. If this does fix the problem, you should be able to determine the rating of the breaker from the markings on the side, or from the owner's manual. Then, you should be able to source a similar breaker from Mouser or MCM (or Radio Shack?).

BTW, is this the original MiniMax or is it the MiniMax CH or NT?

 

[TAH]

Craig,

Thanks for replying.

First off, it's an original MiniMax.

As I mentioned, I'm not an electrician otherwise I might have thought of bridging the breaker! Seems like a simple test. That being said, since I posted the message I called Pentair and they said there is a replacement transformer without a breaker - i.e. the breaker is obsolete and not needed. I ordered one online (just $32 with shipping - a lot less than a pool company service call) so I'm going to try putting that in, especially as I suspect the transformer is bad judging by its condition - somewhat corroded, peeling, etc.

However, one thing that just popped into my head is that if the transformer is taking the power down to feed the electronics in the heater, then is that circuit breaker downstream from the transformer to prevent too much juice from going into the electronics if the transformer fails? That would seem to fit with my belief that the transformer did fail. Again, this is a non-electrician talking. It would also imply that bridging the breaker would send too much power into the unit. Lastly, that makes me wonder what happens if I put in the new transformer without a breaker and it fails eventually - could that fry things?

Any thoughts would be appreciated.

Regards,

Tom

 

[CraigMW]

Sending too much voltage to the electronics is unlikely. When a transformer burns out, it usually just opens the circuit on one of the coils. Do you know if the breaker was on the primary (e.g. the power side) or the secondary (e.g. electronics side)? I guess it is possible that a primary could energize a secondary directly if it burned through its insulation in some transformer configurations (e.g. toroidal and other situations where the primary is wound around the secondary), but this would require a common connection between the primary and secondary (e.g. ground) and would not likely be seen for a power transformer. So, I don't think you would have a failure mode that would lead to over-voltage on the secondary. The breaker could be there to protect the transformer (or electronics) if there was a short in the system. If they don't deem it necessary, then I wouldn't worry about it. BTW, you can test for a short by disconnecting the transformer wires and testing the resistance between the leads. You should get either open circuit (e.g. infinite ohms) or a relatively high resistance. A short circuit would be zero or very low resistance. A simple test with a multimeter should tell you if you are concerned about it.

 

[TAH]

Good to know it's unlikely to send too much voltage to the electronics. At least it's an older model without much in the way of newer displays with more electronics to fry.

I'm not certain which side the breaker is on from an electrical standpoint but it is definitely on the secondary side physically.

Not sure if I'll play around with the a multimeter but I will definitely post when I install the new transformer to let you know what happened. Will probably be several days before it shows up though. Hopefully by the weekend (although it's supposed to be very hot over the next few days - I'm in NJ - and I don't think we'll actually need the heater!).

 

[CraigMW]

No problem. Just install the new transformer as per either the instructions, or looking carefully at how the old transformer was connected. Make sure you know which side is to hook to the power and which side is to hook up to the electronics. Messing that up would indeed fry your heater internals. Once it arrives, let us know.