GFCI breaker for pool heat pump

[kwired]

This I've heard this but I use siemens for my normal supplier so have not had this issue and others appear to not have issues when using their product in this application.

My question is what is Siemens doing different that their GFCI's seem to play better with some items than most other GFCI's?

Have to presume for now that they are meeting listing requirements, hopefully they don't end up pulling an FPE on us.

 

[letgomywago]

My question is what is Siemens doing different that their GFCI's seem to play better with some items than most other GFCI's?

Have to presume for now that they are meeting listing requirements, hopefully they don't end up pulling an FPE on us.

I've tested the 2pole 20 amp on a multiwire with a gfi plug tester and it trips. The 20 amp 2p and 50 amp 2p have the same exact externals so I'm sure the internals are almost the same. They both have 6 awg neutral pigtails. Beyond that you'd need to do some Volkswagen type testing to see if something fishy is going on.

 

[don_resqcapt19]

My question is what is Siemens doing different that their GFCI's seem to play better with some items than most other GFCI's?

Have to presume for now that they are meeting listing requirements, hopefully they don't end up pulling an FPE on us.

I have been told that they have included some high frequency filters and have set the unit to trip closer than the maximum permitted time to trip in the standard. The standard would permit almost 5 seconds for a 7 mA fault and a one second trip time for a 20 mA ground fault. Most GFCIs on the market trip much quicker than the maximum permitted trip time.

 

[retirede]

Not familiar with swimming pool heat pumps, but at same time seems likely they will be outside. Indoor pool in a cold climate area - maybe geothermal heat pump has a higher likelihood? If so I could see it not being outdoors.

The OP states outdoor pool with a Pentair heat pump. I don’t think Pentair makes a geothermal type.

 

[mbednarik]

My question is what is Siemens doing different that their GFCI's seem to play better with some items than most other GFCI's?

Have to presume for now that they are meeting listing requirements, hopefully they don't end up pulling an FPE on us.

Siemens manufactures "Pentairs" brand of GFCI breaker as well.

 

[Jraef]

My question is what is Siemens doing different that their GFCI's seem to play better with some items than most other GFCI's?

Have to presume for now that they are meeting listing requirements, hopefully they don't end up pulling an FPE on us.

Inside of the GFCI device is a printed circuit board with a microcontroller. In the code for that microcontroller is an algorithm that is what “decides” when to trip and not trip. Every manufacturer comes up with their own algorithm, then the breaker gets tested by UL based on whether it TRIPS correctly, but the UL test criteria does not care about nuisance trips. So Siemens’ algorithm is apparently better at discriminating out some of the triggers for nuisance tripping than other brands. To be fair, there may be triggers that other brands do better than Siemens, but this one for inverter driven loads is the one at okay here.

The recommendations started from Hayward and Pentair variable speed pool pumps that used inverter driven motors, because when they first came out, nuisance tripping was a huge issue and was affecting their sales of variable speed pumps. So they discovered through trial and error that the Siemens algorithm worked better on inverter driven loads. Now they sell their own pool and spa sub panels under their names, but I suspect they are Siemens breakers brand labeled.

 

[kwired]

Siemens manufactures "Pentairs" brand of GFCI breaker as well.

I kind of figured that the "Pentair" one is mostly a rebranded Siemens unit.

Seems to be only Siemens product worth buying to me at this time anyway

Have had a lot more troubles with components in their pump panels failing than with Square D or Allen Bradley. Latter two I mentioned occasionally have a fried contactor coil - but that is to be expected when lightning is often the cause. Occasionally a more direct strike means replacing the entire panel regardless who made it.