surge protection opinion

[hockeyoligist2]

We keep having a pump controller getting fried during storms. The controller is 120v from a transfomer located in the same box, 480 feed which supplies the transformer and the pump motors (submersible pumps). Nothing else gets blown out. IYO would surge protection be better on the 480 or the 120 or both? I did notice today when I replaced it (my first time replacing) that the secondary side out the transformer didn't have a connection to the ground so I installed one.

 

[charlie tuna]

you didn't discribe how important this pump was ????? if it's worth $110.00 to keep it running i would install a small 120 volt ups unit between the 120 volt power source and the control circuit. you might have found the problem if one side of the control transformer was missing --- this could cause voltage fluxuations both high and low!!!!!!!!!!!!!!!!!!!!

 

[petersonra]

We keep having a pump controller getting fried during storms. The controller is 120v from a transformer located in the same box, 480 feed which supplies the transformer and the pump motors (submersible pumps). Nothing else gets blown out. IYO would surge protection be better on the 480 or the 120 or both? I did notice today when I replaced it (my first time replacing) that the secondary side out the transformer didn't have a connection to the ground so I installed one.

I doubt the lack or presence of a ground on the X0 of the transformer will make any difference. It seems to me I read once that these things are deliberately not grounded for some reason. Did you check the manufacturer's literature? Did it have OCP on both legs of the secondary side of the transformer?

Normally it is not all that easy for a high frequency transient (AKA surge) to get through a transformer. Is it possible the transient is entering the controller from the low voltage side?

Do you see any blackened wires?

When you say fried what do you mean?

 

[hockeyoligist2]

I doubt the lack or presence of a ground on the X0 of the transformer will make any difference. It seems to me I read once that these things are deliberately not grounded for some reason. Did you check the manufacturer's literature? Did it have OCP on both legs of the secondary side of the transformer?

Normally it is not all that easy for a high frequency transient (AKA surge) to get through a transformer. Is it possible the transient is entering the controller from the low voltage side?

Do you see any blackened wires?

When you say fried what do you mean?

By fried I mean two of the relays on the board were burned.
OCP on one leg of secondary.
No blackened wires.
The transformer has no literature, it is about 10 years old, can't even read the nameplate.
It is possible the transient is coming from the low voltage side. It is operated by 4 floats (mecury switch type) and one of them is about 150' away.
It is a very old system very bad environment (sewer) all the wires were corroded so I cut of the ends and redone all of them. I also went ahead and put surge protection on both the 480 and 120.