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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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My name is ***** *****. I'm trying to replace the fuse to my

Customer Question

Customer: Hey my name is ***** *****. I'm trying to replace the fuse to my SSU switch, and when I flip the switch to "on" the fuse always blows. I just installed new wiring from the breaker to the SSU switch, and I think I've set up the wiring correctly.
JA: Thanks. Can you give me any more details about your issue?
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Submitted: 1 year ago.
Category: HVAC
Customer: replied 1 year ago.
Here's the backstory: the combustion fan stopped working one day. . .so I took the panel off, put the panel back on while re-engaging the safety switch, and the furnace worked again. However, next day the same thing happened, and taking off the panel didn't work.I had an HVAC guy come out here and look at it, and he said before he could do any work on it the furnace needed a dedicated electrical line. So I've put in the electrical line and have installed a new SSU switch (the electrician and the HVAC guy said there was something weird with the wiring going to the furnace, so I just replaced it all).Anyhow, I've got the correct fuse for the SSU switch (15 amps--same ampage as before), but when I turn the switch to "on" it blows the fuse.AMS80703ana = model #04096 69848 = serial number.Power Supply 115 volt 1 pH 60 Hz
Expert:  gotoman for ac replied 1 year ago.

Disconnect wires from furnace . Tope off and turn on power. Russ

Expert:  gotoman for ac replied 1 year ago.

Disconnect power from furnace and turn power back on to see if the fuse blows. Russ

Customer: replied 1 year ago.
hey Russ, when you say disconnect power, what do you mean exactly? Because I had just wired it, meaning it had no power to begin with, then when I powered it up, flipped the SSU switch to "on," the fuse blew.
Expert:  gotoman for ac replied 1 year ago.

What fuse blew. One inside inside furnace. Russ

Customer: replied 1 year ago.
The SSU switch fuse.
Expert:  gotoman for ac replied 1 year ago.

Make sure wiring is correct, Sounds like a direct short. Wire touching wire or ground. Check the connection going into furnace. Where is goes thru box connector . If you have an ohmmeter you can trace the ground by touch wire going to furnace and ground. Russ