Data and power in the same flex to a boiler.

[JohnW2]

Indeed, but you posted about impairment in reply to my comment about someone applying 230V to a 20V input, so it seemed reasonable to me that you were talking about an impairment which caused that.

Fair enough, but whatever assumptions 'seemed reasonable' to you, I have now clarified what I meant.

Kind Regards, John

 

[JohnW2]

No. But I do have to deal with the problem it causes when others do it.

Fair enough. It sounds as if the boiler's control circuitry has probably not been designed with enough consideration of possible 'interference' since, even with separate cables, there is always the possibility of 50Hz 'noise' being around. Is it just one make of boiler that suffers from this problem?

Kind Regards, John

 

[flameport]

eBus is designed to operate using twisted pair wires.

Using anything else will inevitably result in problems.

 

[ban-all-sheds]

I know the manufacturer doesn't allow it.
I wanted to know if the electrical regs did.

They allow the mixing of different voltage bands in the same cable or containment system as long as all the conductors are insulated for the highest voltage present. Which of course they would be in a 5-core flex.

However - as the manufacturers say don't do it, and it is known to cause problems if done, then IMO doing it is not "taking account of the manufacturer's instructions", and it is a contravention of regulation 134.1.1:

Good workmanship by skilled or instructed persons and proper materials shall be used in the erection of the electrical installation. The installation of electrical equipment shall take account of manufacturers’ instructions.​

 

[bernardgreen]

Consider the damage to expensive electronic components that could result if the cable was damaged and 230 volts shorted to 24 volt circuits.

Using separate cables for 230 volt circuits and ELV circuits would reduce the risk of having to fork out for a new PCB and/or other expensive replacement parts.

 

[JohnW2]

Consider the damage to expensive electronic components that could result if the cable was damaged and 230 volts shorted to 24 volt circuits. Using separate cables for 230 volt circuits and ELV circuits would reduce the risk ...

One cannot argue with that statement, but I would say it relates to an extremely low risk.

Kind Regards, John

 

[John D v2.0]

Consider the damage to expensive electronic components that could result if the cable was damaged and 230 volts shorted to 24 volt circuits.

Using separate cables for 230 volt circuits and ELV circuits would reduce the risk of having to fork out for a new PCB and/or other expensive replacement parts.

True but you could equally say this unless it was armoured cable

Consider the damage to your heart that could result if the cable was damaged and 230 volts shorted to your arm.

 

[bernardgreen]

True but you could equally say this unless it was armoured cable

""Consider the damage to your heart that could result if the cable was damaged and 230 volts shorted to your arm.""

Armoured cable when crushed can have multiple core to core shorts withing the armouring without any escape of 230 volts from the cable.

Bottom line is that mixing control ( ELV ) circuits with 230 volts in the same sheath is not good industrial design practise.

 

[John D v2.0]

@bernardgreen that's why I said"unless"

 

[JohnW2]

@bernardgreen that's why I said"unless"

Quite so.

For what it's worth, my personal view is that the risk bernard has mentioned is so small that it wouldn't worry me - so that (provided insulation was adequate), I would have no problem having LV and ELV in the same cable, per se. However, for reasons that have been discussed, I would be hesitant to have 50 Hz 'power' and 'data' cores within the same cable (or even in very close separate cables), regardless of the voltages concerned.

Kind Regards, John