You stated electronic rather than electrical, so I would start with this for electronics, perhaps an earlier version (2nd edition?) Which will be considerably cheaper (£20)...
Well it's a pretty common issue with the cheaper microprocessors out there.
If there is no supply to the main controller, but there is to one of the i/o ports the current can flow into the controller and destroy it. If the supply is there the relative voltage across the protection diodes is...
Given that, it probably makes sense to TT the shed, unless you can be sure it doesn't act as an extraneous-conductive-part. (The SWA won't have sufficient cross section for ECP bonding.)
Just being metal doesn't necessarily mean that it could introduce a potential from outside, it could...
The problem is that the electronic circuit is, say energised and has a detection feed from the output, when it's the correct way round and it trips or is switched off, the detection circuit is dead, but the main circuit is still energised. All good.
However if the wrong way round, when it...
Looks like you buy the one emergency exit luminaire, and select the appropriate signage rather than having to buy the correct luminaire with the correct sign for each application.
5A plug just looks like a standard BS 546 type d to me, what is it if its not?
It's to do with the detection/test circuit if they're tied specifically to one side, then they may not work with the wrong direction, and would still be energised when off. The manufacturer is the only one who knows if this is a problem or not.
You will need to fully test the cable prior to anything, if it's OK, don't use a RCBO use a MCB in the cu if you can.
If not, you need to split the tails and take it into a kmf and feed the shed from that.
Personally I would use RCBOs rather than a RCD and MCBs in the shed.
The only reason...
I think it's probably B)
It amounts to "where a RCD may be fed from either direction, it must be suitable for feeding in either direction"
Or perhaps even more succinctly "equipment has to be suitable for the application "
I know they're both a bit brief for inclusion in a modern standard...
If you do have to upgrade the switchgear, an alternative solution is to house the whole setup inside an enclosure.
This is pretty commonplace in industrial situations where everything is housed in the one panel.
Obviously each cable will need glanding or similar through the enclosure (just...
6.35kV to earth.
Not 5.5kV
It's a single phase supply formed from two phases of the 11kV three phase system, not a single phase supply centre tapped for the earth.
The earth is formed from the star point of a 33kV/11kV transformer secondary (usually - there are actually other ways of...
As said above the maximum normal current in each pole (phase and neutral) is 63A
If you have balanced correctly across the three phases the current in the neutral will be zero.
As for your kW question, there isn't enough information, it could be that 19.9999kW of the 20kW is in the 3 phase...
Personally I would write a formal risk assessment , it has to be by or with the involvement of a skilled person (you an al.) And located with the EICR/EIC.
That would be compliant, whether you charge extra (probably) is up to you, but I would point to the exception to 411.3.3.ii as resulting...
You should note, the "New tenancy" only refers to the FIRST tenancy (3.1c above)
Basically upon the introduction of the law:
3.1ci says the first inspection must be carried out before the tenancy (if not already a tenant)
3.1cii says the first inspection must be carried out before 1st April...
You don't say where you are, but in England, there has to be an EICR done at least every 5 years, and you as the tenant must be supplied with the report within 28 days of the test, and to any new tenant prior to the tenancy.
This is under the Electrical Safety Standards in the Private Rented...
Yes, there is a cure.
Just like other addictions, the first step is accepting that the addiction is a problem.
If you don't take that first step, then it isn't a problem and doesn't need curing!
Any other "problems" - just ask!
Agree, overall the cable may be FUBARed, however in diagnosing the high Zs the IR results don't help.
I would have spent the time finding the high resistance fault as the priority.
Once that's found, it may mean the cable needs repair/replacing anyway.
Ze o
You don't appear to be clear with the problems here.
You talk about insulation resistance of 2.36 to 4.27 - is this Mohm?
This is irrelevant to the Zs
You don't appear to know the differences between insulation resistance, Ze and Zs.
If you do have Ze of 0.16 ohm at the feed end...
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