Wil Posted August 16, 2010 Share Posted August 16, 2010 Just a quick Q: I'm going to be running Shockwave's old Crown power amp (1900 watts) and a Sansamp RBI - both require a kettle lead. Can I use a dual ended kettle lead to save on cabling (like the type occasionaly used with multiple desktop PCs/servers) considering the sansamp is unlikely to draw a lot of current? Quote Link to comment Share on other sites More sharing options...
franzbassist Posted August 16, 2010 Share Posted August 16, 2010 I did this with my Demeter/Peavey setup, and it worked absolutely fine. Nice and tidy too! Quote Link to comment Share on other sites More sharing options...
Wil Posted August 16, 2010 Author Share Posted August 16, 2010 Brilliant. I hoped as much! Quote Link to comment Share on other sites More sharing options...
basshead56 Posted August 16, 2010 Share Posted August 16, 2010 I did the same with my Fender 400Pro head with the Fender ract tuner that came supplied with it-seeing as I had to swap out the transformer (she was a Yank). My tech spliced in the tuner to the amp and I ran a dual kettle lead. Poifect! Quote Link to comment Share on other sites More sharing options...
flyfisher Posted August 16, 2010 Share Posted August 16, 2010 As long as the dual kettle-lead plug fuse hasn't been replaced with a bolt or wrapped in silver foil (yes, I've seen it done!!) then the worst thing that can happen is that the 13A plug fuse will blow if the lead is overloaded. Obviously inconvenient in the middle of a gig, but not actually harmful or dangerous. That's what fuses are for, after all. I recently bought a plug-in power-draw meter from Maplin (about £7) and it's proving to be very useful for checking this sort of thing when we turn up somewhere and plug everything into muliple plug-blocks all leading to a single 13A socket. Quote Link to comment Share on other sites More sharing options...
BigRedX Posted August 16, 2010 Share Posted August 16, 2010 While it's physically possible, it would be very poor electrical practice to run both devices off the same plug and therefore the same fuse. The Sansamp only draws 5W while the Crown poweramp will be drawing at least 1.5 times the maximum output power and both should have different rated fuses in their plugs. In order for the set up to work you'll need to fit the plug with a fuse rated for the device with the highest power consumption otherwise it will be blowing all the time. This means that the lower power device could develop a fault that will not blow the fuse as it's rating is too high. Don't be cheap. Buy a proper mains distribution board and plug each device into it with its own plug and properly rated fuse. Quote Link to comment Share on other sites More sharing options...
Wil Posted August 16, 2010 Author Share Posted August 16, 2010 But I am cheap! Quote Link to comment Share on other sites More sharing options...
flyfisher Posted August 16, 2010 Share Posted August 16, 2010 [quote name='BigRedX' post='926381' date='Aug 16 2010, 12:56 PM']This means that the lower power device could develop a fault that will not blow the fuse as it's rating is too high.[/quote] It depends, of course, on the type of fault the unit develops. But the sort of fault that will cause the plug fuse to blow will likely be some sort of short and will blow a 13A fuse just as well as a 3A fuse (OK, it will take fractions of a second longer to blow). Anyway, a 5W device will only draw about 0.02 amps, so even a 3A fuse will be 150 times the rated power. Are you suggesting that if it develops a fault it won't blow a 3A fuse because the rating is too high? I appreciate the principle of one device per plug, but in practice it can take up a lot of room and 13A plugs are complete overkill for the vast majority of appliances. Also, there must be millions of appliances around the country running off 13A fuses in their plugs when only a small percentage actually need anything more than 3A. In fact, even 3A is often way more than what's needed, yet 1A fuses are not commonly available. If this was a serious safety risk then it would surely have been sorted out long ago. Quote Link to comment Share on other sites More sharing options...
Wil Posted August 16, 2010 Author Share Posted August 16, 2010 As long as my rig doesnt catch fire... Quote Link to comment Share on other sites More sharing options...
flyfisher Posted August 16, 2010 Share Posted August 16, 2010 Well, there are no guarantees . . . Even with 'correctly' fused plugs, it's possible for a fault to cause overheating without blowing the fuse, but actually catching fire is unlikely. Components are made of fire-retardant materials as are printed circuit boards (or should be!!). Plus, our bass rigs are not exactly unattended so any overheating problems would soon be noticed. Tripping over loads of trailing wires from one-lead-per-device is probably more of a hazard than tidying everything up with dual lettle-leads. And driving to a gig in the first place is probably the most dangerous thing of all! Quote Link to comment Share on other sites More sharing options...
BigRedX Posted August 16, 2010 Share Posted August 16, 2010 They're both rack mounting units, so ideally they should be in a rack case with a rack mounted distribution board and everything properly fused. That way there's only the single lead which ought to be run somewhere where it's not going to be in the way of feet, and if it is then it should be properly taped down. However in the end it's your gear and your life. Quote Link to comment Share on other sites More sharing options...
flyfisher Posted August 16, 2010 Share Posted August 16, 2010 (edited) [quote name='BigRedX' post='926449' date='Aug 16 2010, 01:54 PM']They're both rack mounting units, so ideally they should be in a rack case with a rack mounted distribution board and everything properly fused.[/quote] Fair point . . . . ideally. But what does 'properly fused' really mean for a 5W device? Edit: Just checked the Sansamp RBI manual and it has a fuse in the kettle-lead socket: 1A for 120Vac operation and 0.5A for 220-240Vac. So there's the answer; it doesn't matter what fuse is in the 13A plug so a dual kettle lead will be perfectly OK. Just make sure you have a supply of spare 0.5A fuses to fit the Sansamp RBI (probably 20mm I suspect). Edited August 16, 2010 by flyfisher Quote Link to comment Share on other sites More sharing options...
Wil Posted August 16, 2010 Author Share Posted August 16, 2010 [quote name='flyfisher' post='926465' date='Aug 16 2010, 02:05 PM']Fair point . . . . ideally. But what does 'properly fused' really mean for a 5W device? Edit: Just checked the Sansamp RBI manual and it has a fuse in the kettle-lead socket: 1A for 120Vac operation and 0.5A for 220-240Vac. So there's the answer; it doesn't matter what fuse is in the 13A plug so a dual kettle lead will be perfectly OK. Just make sure you have a supply of spare 0.5A fuses to fit the Sansamp RBI (probably 20mm I suspect).[/quote] Coo, thanks! Reassuring to know it has some protection "built in". Quote Link to comment Share on other sites More sharing options...
flyfisher Posted August 16, 2010 Share Posted August 16, 2010 Don't forget that most mains plugs around the world don't include fuses anyway, so if you used your rig in, say, the USA the cable to the wall-socket wouldn't be fused at all - hence why appliances with 'universal' power inputs have their own fuse arrangements. Just don't expect a UK plug fuse to fit the fuse holders of the equipment in question - a good reason to have a set of spare fuses for regularly gigged gear. Quote Link to comment Share on other sites More sharing options...
Wil Posted August 16, 2010 Author Share Posted August 16, 2010 When I was younger I used to have terrible trouble with the main fuse blowing on my Yamaha YB100 motorbike. As a result, I always made sure I carried a universal, one size fits all fuse repair kit. It's a shame they dont make kit kats with a conductive wrapper anymore. Quote Link to comment Share on other sites More sharing options...
flyfisher Posted August 16, 2010 Share Posted August 16, 2010 Quote Link to comment Share on other sites More sharing options...
Happy Jack Posted August 16, 2010 Share Posted August 16, 2010 There you go - sorted: [attachment=56775:fusereplacement.jpg] Quote Link to comment Share on other sites More sharing options...
Wil Posted August 16, 2010 Author Share Posted August 16, 2010 Of course, the perfect fuse would be one that could never inconveniently blow. I mean, what is it with fuses blowing all the time? You'd think they'd make them out of sterner stuff, wouldn't you? You spend all that money on an amp and get given a cheap little fuse in the plug. Charming. Hence, from now on I shall be using... this inanimate carbon rod! Quote Link to comment Share on other sites More sharing options...
obbm Posted August 16, 2010 Share Posted August 16, 2010 If both items of equipmmnt have input fuses then they are protected. The fuse in the plug is only there to protect the cable. As long as the cable is rated for the total load and the plug fuse is correctly rated for the cable then everything should be fine. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.