Discuss Water heater in the Central Heating Systems area at ElectriciansForums.net
hope they're more than 2m. can't have bathroom corona transferred to a kitchen.How close together are the rooms?
possibly they put a glass to the walls.How close together are the rooms?
A customer of mine has asked for a water heater to be installed that will satisfy a kitchen and bathroom. No room heating. Any suggestions.
I find that crazy. No overload protection. How many would leave it out?bear in mind that overload protection is not required, only fault protection.
how can it overload. it's a fixed load. it can go open, in which case it won't work, or it can short (or the cable to it) in which case you have short circuit protection (fault protection).Assuming a 100A supply of course.
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I find that crazy. No overload protection. How many would leave it out?
You can still get overload (a fault) without fault protection kicking in.
The element cover can break down with the L in contact with water raising the current draw not tripping on fault but overload. I have seen it happen. If there is a spur off a 32A ring via a J-box, only to say an immersion heater element, I believe the regs say no fuse is needed on that spur (fixed restive load), while everything else seems to need one, even a spur to a garden office or garage - not 100% sure on that. To me that is total nonsense. The cost of putting in over-current protection is pennies.How can you get an overload on a fixed resistive load such as a water heater?
There is (almost) always will be over current protection as the regulations require protection of cable against a short.The cost of putting in over-current protection is pennies.
The element cover can break down with the L in contact with water raising the current draw not tripping on fault but overload. I have seen it happen.
The cost of putting in over-current protection is pennies.
Where you see the difference is something like a garage feed (again!) when you might have a planned load of, say, 20A and select a cable to match, then the garage CU has a 20A MCB that provides the overload protection. But the feed for the cable might be a 40A or more fuse that will clear in under 5s on a short but is not offering overload protection for the 20A-rated cable.
In an industrial setup that would be the classic example for sure: the feed OCPD is simply for hard faults and there is another system (i.e. the motor starter) that is engineered to have the appropriate time/current characteristics needed to protect the motor against overload in operation.A better example would be a feed to a motor starter where the overload protection is incorporated in the starter.
I have seen a j box in a 32A ring forming a spur, serving only an a 3kW immersion with only a 20A switch between the immersion heater and j box. Well it had a flash neon light on it to make it look better. No over-current protection whatsoever except the 32A mcb at the main CU. A 3kW immersion's current draw is not constant as it depends on the voltage, which may fluctuate during day for various reason.For a heater the distinction is probably academic, if you have a load taking X amps then you size your cable for that and fit a MCB at the matching level. So it would be unusual for the OCPD not to also provide overload protection.
Someone disagrees with you so they are a troll eh. I noticed you trolled all around my posts - that was not coincidence. When you posted it says, to cut it short, only post relating to the topic, otherwise do not. Take note.Hopefully the mods will find a can of this soon
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