How can I stop garden mulcher blowing fuzes?

bmay529

Every time my electric garden mulcher jams it blows the fuze on my fuze board (I have the old style fuze board that doesn't have trip switches) and that happens all too often. I have a micromark mm20260 on the mains lead that has a test button and is rated trip current 30mA. I thought that would trip before blowing the fuze but I am obviously wrong. Any suggestions about what I should use would be welcome.

brightspark

The 30mA trip current is for earth leakage, (to protect you if you cut the cable :eek:). It's not designed to trip for an overload situation.

A few questions for you before I can suggest anything.

1, What size is the fuse that blows on your board?

2, What size fuse do you have in the plug top?

3, What is the make and model of the mulcher?

4, What is the wattage of the mulcher?

bmay529

I take the point about the cut cable protection and that's still important... I'm using an extension cable and also use it with an elect hedge strimmer.
board fuze is 10a
plug fuze is 13a
mulcher is Black and Decker GS1800
1800watts (I think)
Can you get something that protects against a cut cable and also trip for an overload?

brightspark

If you have a board fuse of 10A protecting a socket circuit you really need to get an electrician in to look at and probably replace it.

Is the fuse holder gauge ring red? (the part where the fuse goes into )

Are there other loads on that circuit? (If there are it's unlikely that any additional added protection to the mulcher would work)

You can obtain 10A fuses for plug tops that would be cheaper and more easily obtained than the DZ fuses. 1800w is more than 7.5A so a 5A wouldn't work at all. (The manual though recommends using 13A fuses, it's possible it has built in cut offs that don't operate until over 10A)


Edit. Just read that a 5A fuse may not blow until just over 8 Amps, might be worth a try?

brightspark

As you are probably using an extension lead anyway you could try something like this. (And still use your micro mark at the socket)

http://www.toolz.ie/index.php?route=product/product&path=387_390&product_id=3783

However as it is also rated at 10A I cannot be certain which will trip first, the fuse or the lead.


I know of adjustable overload devices used in industrial environments, but not in a convienient plug/socket arrangement.

brightspark

Regardless of everything else, you seriously need to get your fuseboard AND wiring looked at by a registered electrical contractor.

It's obviously an old board if it is supplying sockets from 10A fuses.

Calahonda52

I agree it needs checking out but the jamming of the machine will draw serious current which is why ten is blowing

brightspark

Calahonda52 wrote: »

I agree it needs checking out but the jamming of the machine will draw serious current which is why ten is blowing

I thought that was obvious.:rolleyes:

What the OP was hoping for was correct discrimination. So that the DZ fuse doesn't blow, but another device trips.

adrian92

If you are using an extension lead (0n a reel) be sure to fully unwind the entire Reel.

If you happen to be using a partially coiled cable reel this could well be the cause of both the machine jamming and the fuse blowing.

brightspark

adrian92 wrote: »

If you are using an extension lead (0n a reel) be sure to fully unwind the entire Reel.

If you happen to be using a partially coiled cable reel this could well be the cause of both the machine jamming and the fuse blowing.

You are correct in saying extension reels must be fully unwound, but the reason AFAIK is that otherwise the heat from the cable is unable to dissipate and can potentially melt or even go on fire. (I have seen a few damaged that way)

Using too long a lead could be an issue as the voltage drop might be excessive, but being coiled won't affect the voltage drop.

bmay529

Thanks Guys. The fuze board is the old type and on the to do list. It has a few breaker switches for things added over the years. Interesting point about the coiled cable. I use a long extension lead (maybe 20m) around the garden that is on a roll with the 30mA current trip but I also have a shorter 6m Plasplugs cassette reel similar to the one you pointed to that has a temp and current cut-out. It shows max power output... reel wound: 4 1/2 amps/1080 watts, unwound: 6 amps/1440 watts. Maybe I could stick this at the end of the long lead to give me a current cut-out if the shredder jams!! Not sure about amps/mA/watts... have forgotten what I learnt at school... will have to refresh!!

brightspark

bmay529 wrote: »

Thanks Guys. The fuze board is the old type and on the to do list. It has a few breaker switches for things added over the years. Interesting point about the coiled cable. I use a long extension lead (maybe 20m) around the garden that is on a roll with the 30mA current trip but I also have a shorter 6m Plasplugs cassette reel similar to the one you pointed to that has a temp and current cut-out. It shows max power output... reel wound: 4 1/2 amps/1080 watts, unwound: 6 amps/1440 watts. Maybe I could stick this at the end of the long lead to give me a current cut-out if the shredder jams!! Not sure about amps/mA/watts... have forgotten what I learnt at school... will have to refresh!!

Your shredder is 1800watts so that small lead isn't suitable!

bmay529

Thanks brightspark. I get it... the one you suggested was 10aamp. Is it that it needs to be at least 7.5 amps?

brightspark

bmay529 wrote: »

Thanks brightspark. I get it... the one you suggested was 10aamp. Is it that it needs to be at least 7.5 amps?

Yes, your shredder will draw at least 7.5Amps when loaded, probably just over 8Amps.

But as I said earlier there is no certainty that the 10A extension reel will cut out before your fuse blows.

Your real problem is your fuseboard is not adequate to supply your shredder.

bmay529

Thanks brightspark