Hi,
I have a garage CU that has two MCBs, B16 for mains and B6 for lighting.
Recently, the B16 started tripping when the tumble dryer is on. There's an old fridge plugged into the same double socket, which I assumed was the culprit. So I unplugged it, and everything else apart from the dryer. MCB still tripped. It all used to be fine, nothing obvious changed but the MCB just started tripping.
I replaced the MCB today, the old one was very hot when I took it out, but no melted insulation on the wiring. All the cores are done up tightly inside the CU. I've unplugged everything in the garage apart from the tumble dryer. The MCB still trips. The RCD doesn't trip so unless it's faulty, I'm assuming there is no short or earth fault on the garage electrics.
I don't get it. Why would a 16A MCB trip before a 13A fuse blew? Indeed, why would a dryer trip a 16A MCB? I can't believe a dryer draws over 3.5kW...
The dryer is only a month old so shouldn't be faulty. Connecting it to the main house main by an extension reel, it run just fine and nothing trips - although the house main is on a 32A MCB.
I guess I'll have to disconnect all junction boxes and sockets in the garage and reconnect them one by one to eliminate a fault. Can anybody suggest a quicker way to find what's wrong? Would it be worth putting a multimeter across the MCB terminals to see whether any current is being drawn with all appliances unplugged?
Any advice appreciated. Unless it's, "call an electrician."
I have a garage CU that has two MCBs, B16 for mains and B6 for lighting.
Recently, the B16 started tripping when the tumble dryer is on. There's an old fridge plugged into the same double socket, which I assumed was the culprit. So I unplugged it, and everything else apart from the dryer. MCB still tripped. It all used to be fine, nothing obvious changed but the MCB just started tripping.
I replaced the MCB today, the old one was very hot when I took it out, but no melted insulation on the wiring. All the cores are done up tightly inside the CU. I've unplugged everything in the garage apart from the tumble dryer. The MCB still trips. The RCD doesn't trip so unless it's faulty, I'm assuming there is no short or earth fault on the garage electrics.
I don't get it. Why would a 16A MCB trip before a 13A fuse blew? Indeed, why would a dryer trip a 16A MCB? I can't believe a dryer draws over 3.5kW...
The dryer is only a month old so shouldn't be faulty. Connecting it to the main house main by an extension reel, it run just fine and nothing trips - although the house main is on a 32A MCB.
I guess I'll have to disconnect all junction boxes and sockets in the garage and reconnect them one by one to eliminate a fault. Can anybody suggest a quicker way to find what's wrong? Would it be worth putting a multimeter across the MCB terminals to see whether any current is being drawn with all appliances unplugged?
Any advice appreciated. Unless it's, "call an electrician."