Jandy JXI400 Heater No Power

[drsisco]

I have a 3 year old Jandy JXI400 heater. This year the heater would not turn on when the breaker was flipped on for season. I pulled the cover off and found a blown fuse. When I replaced the fuse and turned power back on it burned up the transformer. Called local technician out and he told me the power distribution board was bad. I replaced the PD board and put new transformer in. Same result. Transformer burned up when I turned it back on. The technician came back out and tole me the ignition control board needs to be replaced. Worry he is just guessing on what the issue is. I ordered another (3rd transformer) and wired it in on power side but not on downstream end. Transformer has 25volts on meter. Any idea on what is causing my transformer to burn up when wired back in to fuse and yellow ground?

Thanks,

Dustin

 

[ajw22]

Welcome to TFP.

Is the heater connected to 120V or 240V?

What voltage is the PDB set for?

 

[drsisco]

The power is set at 240V and the PDB is also set for that.

 

[ajw22]

Did you verify voltage with a multimeter?

 

[drsisco]

Yes with my multimeter on the PDB and the breaker. The technician that I hired also verified it.

 

[swamprat69]

When you replaced the fuse was it an exact match for the one that as blown? That fuse is the protection for the transformer.

 

[drsisco]

Not the exact brand. The numbers on the top were the same but the inside looks different. I have tried to find the fuse info in the book i have but it is very weathered from my wet garage. I will get the details off it when i get home and reply.

 

[swamprat69]

It should be a 2 Amp fast blow glass fuse. Most fast blow glass fuses have a small thin wire inside. Slow blow fuses have either a coiled wire or a flattened ribbon wire and are meant to blow only under a sustained overcurrent load. If you have larger than a 2 Amp fuse or a slow blow fuse, you are protecting the fuse rather than th transformer.

 

[drsisco]

Thank you for the help.. I did not know that. I will ask the pool people is they sell the fuse. I hope that is the only issue.

 

[swamprat69]

That will still not address the core issue. It would appear that you have a direct short to ground on the low voltage side of the transformer. You will need to track the short to ground down or you will just keep blowing fuses instead of the transformer.