I recently had a power outage that blew one of our air conditioning fuses (which we were able to fix) and one of the fuses (out of two) in our spa equipment service control board. Next to both fuse slots it says 3 amps, but the fuse that blew had this written on it:
BUSS GMA
3·15A 125V
(it is about 19 or 20 mm long)
Does that mean its 3.15 amps, 3 amps, 15 amps? I thought it was supposed to be 3 amps since it clarifies that on the circuit board so I got a 3 amp 20 mm bussman fuse from Home Depot.
It came with two fuses and one blew like a firework so I don't want to put the other one in with the chance that there is a short circuit causing it. Any help would be appreciated.
Here are some pics
Original fuse- http://imgur.com/crx3jvi
Pics of the service panel circuit board–
http://imgur.com/a/7733C
Is there a short circuit or should I just try getting a 3.15 amp 125v fuse (instead of 3 amp 240 volt fuse)
Best Answer
3.15A is indeed an appropriate value for a BUSS GMA 5x20mm fuse.
Chances are something else is blown out. If you're not up to doing component level troubleshooting, probably a board will have to be replaced.
One part that frequently takes the brunt of power surges is MOV (varistor) devices, which look like big (often red or blue) ceramic disk capacitors.
It would be very close to the fuse, and, if there is a series fuse, will typically fail shorted so that when you replace the fuse it will blow again. The other possibility is that some kind of switching supply has failed shorted which would typically involve replacing semiconductors. Most service these days just involves tossing the module and replacing it, so you might want to check out the cost of a replacement board.