Heating changed from gas to electric - overloading or safe???

[janthehulaman]

In this large community center they decided to replace the gas central heating with electric. Upstairs some 19 new panel heaters were connected to about 4 ring main circuits, some were spurred, others just with 13a sockets. The heaters are 1 Kw but 2 are 1.5Kw. Upstairs everything runs off a distribution box that has a large number of outlets and the master switch is rated at 100 Amps. Off this box also there are 2 hot air driers for the toilets, kitchen things, electric hob, kettle, toaster, there are 5 air conditioning units, large office area with about 14 computers + servo room & printer and I would guess about 100 large LED ceiling panel lights. Also there is a water heater feeding the upstairs toilet area. Given that 1st thing in the morning when the building will be cold, all the heaters will be turned on + kettle + cooker hob + all the lights & computers running, all the lights on, is this OK, it's well above 100 Amps. Excuse my ignorance but it does not feel right.

 

[dmxtothemax]

I would suggest that you monitor the power used by that panel,
once you have definite figures to work with, then you can make changes.

 

[bigspark17]

I would suggest that you monitor the power used by that panel,
once you have definite figures to work with, then you can make changes.

What would you suggest is used to monitor this?

 

[suffolkspark]

Gas out electric in.... Whoever made that decision needs a slap

 

[Wilko]

Hi - it's hard for us to say whether the installation is safe. That assessment must be made (in the first instance) by the folks who made the changes and signed off the Electrical Installation Certificate. My thought would be to get a copy of this cert (from the person who ordered the work) and talk with the signatories. Then you'll either be reassured, or not. Another direction is to commission an independent Electrical Installation Condition Report to specially look for signs of load damage, for example.

 

[The Ghost]

Impossible to conjecture upon. Is the supply three phase or single phase? Do you have any pictures you can show us of the supply gear? Are the aircon stand alone on the wall, or cassettes? Are they for heating as well as cooling? What rating are the LED lights? Too many unkowns to answer your question really.

 

[janthehulaman]

Thanks very much for replying, when I'm at the centre next (Friday) I'll take some photos. But from memory the whole building has a 3 phase supply and one phase is supplying this what really is rather like a large consumer unit whose master switch is rated at 100 amps and from this come all the upstairs circuits via mcb's. So 15 heaters at 1 KW 2 at 1.5 KW 15 computers at 300 watts 100 LED's at 20 watts, 1 kettle at 2 KW, 1 hob at 3 KW, 5 air con' units heating up at 3 KW, and hot water heater at 3 KW, all these things would be on simultaneously on a cold morning when the place opens.... so that 47.5 KW or 197 Amps

 

[janthehulaman]

Impossible to conjecture upon. Is the supply three phase or single phase? Do you have any pictures you can show us of the supply gear? Are the aircon stand alone on the wall, or cassettes? Are they for heating as well as cooling? What rating are the LED lights? Too many unkowns to answer your question really.

Thanks very much for replying, when I'm at the centre next (Friday) I'll take some photos. But from memory the whole building has a 3 phase supply and one phase is supplying this what really is rather like a large consumer unit whose master switch is rated at 100 amps and from this come all the upstairs circuits via mcb's. So 15 heaters at 1 KW 2 at 1.5 KW 15 computers at 300 watts 100 LED's at 20 watts, 1 kettle at 2 KW, 1 hob at 3 KW, 5 air con' units heating up at 3 KW, and hot water heater at 3 KW, all these things would be on simultaneously on a cold morning when the place opens.... so that 47.5 KW or 197 Amps

 

[Wilko]

Hi - if it did pull 200A a typical 100A BS88-2 suppliers fuse will last for more than 10 minutes before melting, but it will melt. Although it's ok to have the CU MCB's ratings adding up to more than the capacity of the board, it is not ok to exceed that 100A in normal use, which is no doubt what your post is about. Time to measure the load

 

[littlespark]

So what does the other 2 phases supply if all this is off one?

You might find this board is also 3 phase, and the loads are equally spread across the 3.

Photos will help.

 

[janthehulaman]

So what does the other 2 phases supply if all this is off one?

You might find this board is also 3 phase, and the loads are equally spread across the 3.

Photos will help.

Thanks, it just might be, so I'll have to photo the board but from memory, I thought it was a single phase as there was only one master switch at 100 A and often you would see a warning note saying 440 volts if the box was 3 phase (there is no notice to that effect), the other 2 phases I would speculate feed the downstairs where the electrical requirements are far heavier than upstairs.

 

[The Ghost]

From what you describe in terms of load for the downstairs, is it possible the main fuses are 200a not 100a? you have described the main isolation switch for the offices etc. as 100a rating but not the main fuses. Just curious, not doubting you. If you are looking at such boxes and loads I hope you are a competent person aware of the H&S and EAW regs etc.

 

[janthehulaman]

From what you describe in terms of load for the downstairs, is it possible the main fuses are 200a not 100a? you have described the main isolation switch for the offices etc. as 100a rating but not the main fuses. Just curious, not doubting you. If you are looking at such boxes and loads I hope you are a competent person aware of the H&S and EAW regs etc.

I certainly not a qualified electrician but would describe myself as a competant DIY 'er. So in terms of electrics I would replace a cracked 13 socket or a lamp fitting and that's it. However seeing what is going at the center, I applied what may be termed as Intuition. In a domestic house with shower and electric cooker etc, if the householder decided to replace the gas central heating with electric panel heaters in every room, somehow it would cross my mind as to whether the electrics was up to that. So in this case I decided to go on this forum and depending on what people would say, to recommend to the CEO of the centre to pay to have an independant survey done to ascertain the position. I did not want the centre to be put to an unnecessary expense if it turned out that the installation was OK. It does seem that my very limited knowledge is not providing all the vital info but I'll do my best!

 

[The Ghost]

Thanks for the reply @janthehulaman and fair comment. I tend toward an assumption of competence on the part of the installers and assume loads have been calculated correctly. Having said that there is no doubt mistakes happen with rogue traders and sounds like you are a good person to have around looking after things and thinking about it all.