I have a 220 volt square D circuit breaker. The circuit breaker does not trip. I also have a 220v, 30 amp, with 2 slow burn fuses in a box near the dryer that is on the same circuit. Over the last year, the right side slow burn fuse burns out about once a week. I just put a new dryer in and now the right side slow burn fuse burns out every other day. I cannot figure out why. Is my main box drawing too much current on one side? Can I delete the slow burn fuse box by putting a plug in the right side fuse holder and just rely upon the circuit breaker. Thank you in advance for any help.
So you have a 220v line that runs from the main breaker panel (is that circuit breaker also 30 amp?) to a subpanel at the dryer which has 30 amp slo-blo fuses (tubular type I presume)...and from there it goes directly to a 3 or 4 wire dryer receptacle? Not usually a requirement for a secondary disconnect next to a dryer...most places the line goes directly from the main panel to the receptacle. If your circuit breaker is 30 amp, then yes, you could take the subpanel out of the circuit....unless your local codes say otherwise. Double check dryer manual to be sure a 30 amp circuit is what's recommended.
It would be nice if you could get your hands on a clamp on ammeter to measure the currents in the two hot 220v leads to see if the current in the "right side" fuse seems higher than it should be, but you may be able to lick your problem without one.
You didn't say whether the fuses were in a "switched disconnect" box or in an unswitched one. And, much of my prattling below assumes the fuses are cartridge types, and not screw in ones.
Either way, from the sound of your problem I'd say there's an excellent possibility that current flow through a poor connection near the right side fuse is dissipating heat which causes the fuse to fail from that heating melting the solder (inside)joining the fuse link to the heated fuse endcap. Carefully cutting open a failed fuse will disclose that, the fuse link itself will be intact and "unblown", but it will be disconnected from one of the end caps.
Try this:
Run the dryer for about ten minutes, then go and flip off the breaker feeding that circuit, with the dryer still running. (When the dryer stops you KNOW for sure you opened the correct breaker and it's OK to stick your hands in the fusebox.)
The run back to the fusebox, open it up and feel that right side fuse's end caps. If one of them is noticably hotter than the other three end caps in that box start looking for a "loose disconnection" near it. Some possibilities are:
A sprung open or dirty fuse clip; Sandpaper the inside and squeeze it down a bit so it grabs the fuse tightly.
A loose clamp screw on a wire clamp near the fuseclip.
A loose screw fastener (or rivet) holding the fuseclip to a current carrying strap which is part of the fusebox.
If it's in a fused disconnect switch there may be a corroded switch contact heating up in close thermal proximity to the fuse clip. DAMHIKT
If you don't feel any unusual heat on the right side fuse's end caps, then You may be cursed with an intermittant short to ground within the dryer, and your chances of finding that on your own are slim and none. (And Slim rode out of town yesterday.)
The current NEC doesn't require a secondary fuse at the dryer location, however it does require a receptacle and plug on the dryer as you suggested. The problem could be caused by a bad connection in the right side fuse block so you are just as well to eliminate it. It would not be surprising for the right side fuse to draw more current then the left as in some clothes dryers, although the heating elements are 240 volt, the motor that spins the drum can be 120 volt, which would account for an imbalance
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.