David R Posted October 2, 2014 Report Share Posted October 2, 2014 On my tank I'm running five 300W heaters connected to a single thermostat/controller (industrial-spec, rated higher than the wall socket) via a single six-point multi-board. The board is rated for 2400W, so should be well within it's comfort zone yeah? Twice today it has popped it's circuit breaker thingy (pardon my technical terminology). Any idea why this might be happening after ~18 months of otherwise flawless operation? It's a good HPM one with individual switches, not the cheapest/nastiest one money can buy. Fortunately the controller has two plugs on it, so I've plugged two of the heaters into there on a double adapter, so if it trips again over night the tank won't go cold, plus the room with the tank is insulated and heated to 22C anyway. Quote Link to comment Share on other sites More sharing options...
Caryl Posted October 2, 2014 Report Share Posted October 2, 2014 Grant says, is the multi board warming up at all? Obviously it is within its ratings but if there is a slight fault within the board or one of the plugs plugged into the board, it could be heating the board slightly. If there is heating of the board, especially by the circuit breaker, it will tend to trip at a lower load than normal. There could be slight corrosion on one of the plugs, or the contacts within the board itself may not be putting enough pressure on the plug pins, which could also be a cause of heating. I would not expect this with an HPM board but it could happen. Quote Link to comment Share on other sites More sharing options...
redracer77 Posted October 2, 2014 Report Share Posted October 2, 2014 If it is when the heaters switch on, it may be from a spike as the elements heat up and draw more current. Not sure why it would start doing it now though. Quote Link to comment Share on other sites More sharing options...
David R Posted October 2, 2014 Author Report Share Posted October 2, 2014 Didn't feel warm when I moved the plugs. And I heard the circuit breaker trip when I was in the garage, I'd reset it about two hours earlier, and it definitely didn't trip when the heaters turned on. I'll check all the plugs for any signs of corrosion tomorrow. Quote Link to comment Share on other sites More sharing options...
Insect Direct Posted October 2, 2014 Report Share Posted October 2, 2014 I've had that before. Think with those cheaper multi boards where plugs barely fit snug in socket. Some multiboards work where others like to pop like popcorn :spop: Quote Link to comment Share on other sites More sharing options...
David R Posted October 2, 2014 Author Report Share Posted October 2, 2014 Still hadn't popped by 0410 this morning when I left for work, maybe the reduced load was what it needed... Quote Link to comment Share on other sites More sharing options...
kinnadian Posted October 2, 2014 Report Share Posted October 2, 2014 That trip switch is typically a 10A trip. That's a lot of current but not impossible for that load, 1500W will nominally draw a little over 6 but as another person pointed out it might be over-drawing on start up. I would just use two multiboards rather than one. Problem should be solved. Quote Link to comment Share on other sites More sharing options...
hovmoller Posted October 2, 2014 Report Share Posted October 2, 2014 I'm pretty sure aquarium heaters don't over draw on start ups. It's just a heating element Quote Link to comment Share on other sites More sharing options...
David R Posted October 3, 2014 Author Report Share Posted October 3, 2014 I would just use two multiboards rather than one. Problem should be solved. That's my plan, I've put all five heaters back on the one board now I'm home from work, but seems how the controller has two outputs I'm going to spread the heaters over two multi-boards, and might chuck a sixth one in there just to speed things up a bit after a water change as it takes a long time to warm up. Shame they don't make three-point multi-boards, this could seriously mess with my OCD! Quote Link to comment Share on other sites More sharing options...
Adrienne Posted October 4, 2014 Report Share Posted October 4, 2014 Not sure if this is any help. I had an issue a while back with our switchboard circuit tripping and the electrician put it down to overloading when everything was on (the everything being all my tanks and equipment on the same circuit). In fact it turned out to be a damaged wire in one of the cords. Is it possible that one of your heaters might be faulty? Quote Link to comment Share on other sites More sharing options...
Ducati4me Posted May 6, 2015 Report Share Posted May 6, 2015 Hi, is the circuit breaker an RCD or overload type? If RCD, one or more of the elements or leads could be leaking to earth. Any electrician should have a tester for this. If overload type, with continued use they tend to get tired causing tripping and may need replacement. Your loads as mentioned by others are well within acceptable ranges but still can could cause this. Better multi box's are available but come quite expensive. Google Jackson Industries in Onehunga or they are easy to make with a little effort. Most parts are available from any electrical wholesaler including 15 amp outlets you can replace your wall sockets with. The comments about the high start up current are correct. Although most meters operate to slow to register this, resistive loads do have high inrush current, somewhere from 5 to 7 times the operating load. this is very short term, only a few cycles. this may also cause tripping. Hope it helps! 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.