ceramic fuse

[rmaher]

Due to a weak battery, I held my finger on the combiner too long and blew the fuse. No big deal, I thought, but try to find a ceramic slow blow fuse like the Buss mda-20 that was in there. Five stores - nada!

Frustrated, I went online; Grainger has them but want $2.00 a piece (and they were by far the cheapest - elsewhere they wanted $5 per fuse!)

Long story, long, I happened to check on ebay and bought 50 of the real McCoy's for dirt cheap. I'm not sure what demand there is for them, but if you could use any, $2.00 for a box of 5 plus shipping (can't be much) makes me whole.

Rob

 

[Bob Bradley]

That's the sort of thing I like to have available. If you email me (rbradley04 at snet.net) your address, I'll drop a few bucks in the mail to you.
Bob

 

[rmaher]

I'm with you - and when I saw them for so cheap on Ebay, I thought of the forum. I hope I never need 50 of these boys!

I sent you an email with my address. Send me yours and I'll drop them into the mail for you now!

Rob

 

[hcalmar]

If the 37C has one on it I am in. Where is the fuse located?
Hal

 

[rmaher]

Mine are in the ER behind the main 12 volt distribution panel (as opposed to the 12 volt circuit breaker panel in the salon!)

 

[Bob Bradley]

Rob,
I received the fuses today. Thanks. I'm a little confused about one thing though - the amperage. I presume that MDA - 20 means 20 amp fuse. Do you know why to the left of that on the case it says "IR 1,500A 250V AC" and beneath that, "IR 10,000A 125V AC"?

20 amp (DC) seems reasonable, as I also presume (I never assume) that the combiner switch operates some sort of solenoid or relay, but what's that stuff about AC?

Oh, and I'll drop an envelope in tomorrow's mail for you.
Bob

 

[Nick]

Rob,

I'll check my 37 main 12 v panel and the electrical drawings and take some also if the fuses are the same. I 'll get back to you next.

Thanks Nick

naandrianas@verizon.net

 

[rmaher]

Bob - I'm way out of my league here but the IR refers to the "interrupt rating". Here's a link to better information about the fuse: http://www.cooperet.com/library/products/MDA_Specs.PDF

Nick - Let me know what you need and I'll get them out to you posthaste.

Rob

 

[Nick]

Thanks Rob!

Why not post the fuse IR question on the forum's gen discussion section and let the electrical engineers give us the scoop!

Nick

 

[ADaily3224]

I blew one of those fuses, it turns out it protects the alternator. Mine blew when I turned on my tower spreader lights. I was traveling through the Welland Canal when it happened. My ships service battery was dead by the time I exited the canal. Stupid me had the alternator out and to the shop, replaced the voltage regulator before I checked the wiring diagram and located the fuse inside the aluminum boxes where the battery isolation switches are mounted. This information may save someone else some time and trouble if they encounter the same thing.
Tony D

 

[rmaher]

I still have quite a few of these if anyone is interested!

 

[jcrlaw]

I'll take a box. Just let me know how to get you the money.

 

[rmaher]

PM me your address and I'll send them to you. You can then drop me a check when you receive them!

 

[Boss Lady]

over current protection devices are complex to describe to the lay person, DC and Ac ratings are part of the equation, as well as where the fuse is in the circuit and what its' function is for that circuit. In a nutshell the interrupt rating is for short circuit protection, and you have to pay particular attention on DC circuits because of long dwell times of the arc if you have a very high current short circuit (plasma arc, like welding occurs at DC voltages). The balancing act occurs when you have to size the fuse for the normal currents the circuit is expected to see under normal loads, and have some headroom to account for those temporary high loads, and yet blow when the overload occurs and without melting the wires carrying the load. Confused yet?

 

[rmaher]

Still have quite a few if anyone's interested!

Rob