Kind of reminds of the US-style "fuse-breakers." Retro-fits for our screw-base plug fuses (w/ a pop-out button on top). They had one flaw, however: in many fuse boxes, there was no room for the button to pop out, if the door was closed. Therefore, they were often useless.
The thing is, if you are constantly messing around with old electrical equipment that you might be testing out or whatever, these resettable fuse/circuit breakers are an absolute godsend. Especially when you landlord is too stingy to upgrade the old electrics to modern day standards. I'm thinking RCDs here.
I was fitting a fire alarm in a local shop and the consumer unit was a white wylex and had the same things along with a 16a mcb conversion I've told the the owner to consider having a new CU for better protection as it's a very old installation.
+9ff70f96 aye your right I am the same our CU is wylex 10 way board and if someone said to me "new regs say metal need to be fitted" I'd say sod off lol.
+9ff70f96 That's because it costs a ton of money to swap things out. If it's still working they see no need to spend all that money, so they won't. I'm the same way. Sod it. If it still works it still works. No sense dropping money I don't have on replacing a perfectly functional setup. Thankfully, the breaker boxes on my side of the pond haven't changed significantly in over 50 years. It's quite fascinating to see the differences in play over in Britian, too. This sort of breaker is par for the course over here. Somewhat. We have them in different casings with screw terminals because we rarely, if ever, have a fuse box with actual fuse wire in it. Our wiring system also leaves a unique situation where a breaker like this, to replace a fuse block, is a *massive* upgrade. Ring mains generally won't have this problem, but we don't use them over here. We use a branching setup instead, where each breaker ostensibly has one room on it and our breaker boxes can have upwards of 20 breakers in them. Our lights are wired the same way many time, as is the case in my house, and a lot of hardwired appliances like cooktops, ovens, central HVAC(Which we almost always have at minimum a central AC but most homes have both electric heating and cooling), the water heater, etc have their own dedicated breakers. In older American houses, the outlets in bedrooms are often either on a very small breaker(5 amps is common) or tied to the breaker for another room. My house is set up in that way, my bedroom's outlets are put on the same breaker as half of my kitchen. This was fine in the 1970s, 80s, even into the 90s when the draw in here was limited to a radio and a boxfan. But today? I've got a gaming PC, a window AC, a radio, an airbrush compressor and two phone chargers in here. If we use the toaster, if we plug the microwave into the outlet it's supposed to be plugged into? They pop the breaker every single time the are used. We have to run the microwave off a heavy duty outdoor extension cord that runs down into the TV room, and we just don't make toast at all. If we had actual fuse wire instead of breakers we'd have long since bought a drop-in breaker upgrade. There's no actual safety issue present, the wall wiring is more than capable of carrying the current demands in place and the wiring in my room is completely separate from the wiring for the kitchen. It's just they were all run to the same 15a breaker instead of separate breakers as they would be in a newer home.
Do these circuit breakers still trip if the 'ON' button is being pressed in at the time? Because modern circuit breakers can still trip whilst the leaver is being forced in the top position.
+jayja45 yes as i had a short in a cable (mouse eaten the insulation) soon as you try and latch it it trip again ,, if you have a RCD or RCBO, on RCD TEST button Never Hold it or you can burn it out if held for a long time on some RCD breakers)
+lee x With the RCD test, most RCD units actually cause a disbalance in the phase/neutral pair (thus producing a Residual current). This is so that when you 'test' the RCD, it actually tests the whole function of the RCD rather than just the tripping mechanism.
+9ff70f96 Yeah, it's pretty standard for that curve even these days. The only issue would be the very low breaking capacity, but as John says, they were intended to replace rewireable fuses, which had a pretty low rupture capacity too
good vid of how these old isolators work, the type of video they should be showing in college classes.
Presumably there was a test spec for the trip time vs current... would have been interesting to see if, 40 years down the road, it still met the spec!
Kind of reminds of the US-style "fuse-breakers." Retro-fits for our screw-base plug fuses (w/ a pop-out button on top). They had one flaw, however: in many fuse boxes, there was no room for the button to pop out, if the door was closed. Therefore, they were often useless.
+Madness832 I often wondered about those while I was in the US, were they thermal only? Or thermal/magnetic like these?
I wonder if not being enclosed in the box meant more heat lost from the bimetallic strip and made it a bit less sensitive?
If there was a fluorescent ballast, or even better a sodium ballast in series with the 'breaker you'd get a nice flash on disconnect.
John, excellent content! Can you do a Vid explaining the various lighting circuits and how to wire them. Sure you'll do it justice!
The thing is, if you are constantly messing around with old electrical equipment that you might be testing out or whatever, these resettable fuse/circuit breakers are an absolute godsend.
Especially when you landlord is too stingy to upgrade the old electrics to modern day standards. I'm thinking RCDs here.
Very interesting, Thanks for the vid!!
Cheers
I was fitting a fire alarm in a local shop and the consumer unit was a white wylex and had the same things along with a 16a mcb conversion I've told the the owner to consider having a new CU for better protection as it's a very old installation.
I find most folk don't seem to care as long as it 'works'.
+9ff70f96 aye your right I am the same our CU is wylex 10 way board and if someone said to me "new regs say metal need to be fitted" I'd say sod off lol.
+9ff70f96 That's because it costs a ton of money to swap things out. If it's still working they see no need to spend all that money, so they won't.
I'm the same way. Sod it. If it still works it still works. No sense dropping money I don't have on replacing a perfectly functional setup. Thankfully, the breaker boxes on my side of the pond haven't changed significantly in over 50 years.
It's quite fascinating to see the differences in play over in Britian, too. This sort of breaker is par for the course over here. Somewhat. We have them in different casings with screw terminals because we rarely, if ever, have a fuse box with actual fuse wire in it. Our wiring system also leaves a unique situation where a breaker like this, to replace a fuse block, is a *massive* upgrade.
Ring mains generally won't have this problem, but we don't use them over here. We use a branching setup instead, where each breaker ostensibly has one room on it and our breaker boxes can have upwards of 20 breakers in them. Our lights are wired the same way many time, as is the case in my house, and a lot of hardwired appliances like cooktops, ovens, central HVAC(Which we almost always have at minimum a central AC but most homes have both electric heating and cooling), the water heater, etc have their own dedicated breakers. In older American houses, the outlets in bedrooms are often either on a very small breaker(5 amps is common) or tied to the breaker for another room. My house is set up in that way, my bedroom's outlets are put on the same breaker as half of my kitchen. This was fine in the 1970s, 80s, even into the 90s when the draw in here was limited to a radio and a boxfan. But today? I've got a gaming PC, a window AC, a radio, an airbrush compressor and two phone chargers in here. If we use the toaster, if we plug the microwave into the outlet it's supposed to be plugged into? They pop the breaker every single time the are used. We have to run the microwave off a heavy duty outdoor extension cord that runs down into the TV room, and we just don't make toast at all.
If we had actual fuse wire instead of breakers we'd have long since bought a drop-in breaker upgrade. There's no actual safety issue present, the wall wiring is more than capable of carrying the current demands in place and the wiring in my room is completely separate from the wiring for the kitchen. It's just they were all run to the same 15a breaker instead of separate breakers as they would be in a newer home.
Thanks for the video.
I have exactly the same breakers in my CU at home. Most of them are 30 years old now. Time for a new CU with RCBO's I think.
Do these circuit breakers still trip if the 'ON' button is being pressed in at the time? Because modern circuit breakers can still trip whilst the leaver is being forced in the top position.
+jayja45 Yes, the trip mechanism is not dependant on the button position.
+jayja45 yes as i had a short in a cable (mouse eaten the insulation) soon as you try and latch it it trip again
,, if you have a RCD or RCBO, on RCD TEST button Never Hold it or you can burn it out if held for a long time on some RCD breakers)
+lee x With the RCD test, most RCD units actually cause a disbalance in the phase/neutral pair (thus producing a Residual current). This is so that when you 'test' the RCD, it actually tests the whole function of the RCD rather than just the tripping mechanism.
Thermal very slow on overload. Ok for the 80tees, at least resetable .
Probably about normal for any B-type MCB?
+9ff70f96 Yeah, it's pretty standard for that curve even these days. The only issue would be the very low breaking capacity, but as John says, they were intended to replace rewireable fuses, which had a pretty low rupture capacity too