In the days before ferrules were widely known outside the panel-building industry, it was quite a popular albeit misguided pastime. For example, we saw a number of small theatre lighting installations with a plug patch at the dimmers, where the flexible patch cords were tinned before connecting...
Is that with the original yellow latch ones or the TOP series with metal latches? I know Neutrik discontinued the original type because of similar problems of them not being robust against incorrect engagement and rotation. We don't give them a particularly hard life in most of our applications...
No, and it's unlikely. It would only really occur where the test is carried out from one live conductor to earth, the other one is shorted or very leaky to earth, and the load is very small and very sensitive. Nonetheless, if one uses a method that never puts 500V across the load, one can never...
If it doesn't make it too hard to manoeuvre the board, that would certainly solve any high-resistance issues and it's the sort of thing I would do if I didn't expect anyone else to have to service the unit in the future.
Most functional leakage is due to capacitance e.g. from filter capacitors connected L-E, and from parts of a circuit that operate at much higher frequencies than 50Hz. Both of these will only occur when the equipment is connected to AC, not when subjected to a DC insulation test.
As an example...
Generally copper conductors will be stranded to one of a number of classes within IEC 60228.
Class 1 = solid conductor.
Class 2 = stranded conductor (e.g. larger T+E, normal 6491x conduit cables) for which terminals in electrical fittings are normally suitable without ferrules or other...
If it's appearing from within the cable i.e. not something that could have oozed out of the building fabric, then I would agree that it is probably plasticiser escaping from the PVC, but of a type that does not attack the copper and therefore does not turn green. (The plasticiser that causes...
All things considered I agree that some of the commercial PDU offerings are either too shoddy, too expensive or both. When we designed racks, we used to design our own PDUs too. But that was in quantity, for large contracts. I wouldn't bother making a one-off for myself these days, like...
The unit appears to be 12 years old and might have had significant runtime. Two likely causes of burnt crimp terminals exist: motor overload / winding failure or high resistance contact at the terminals themselves. Because the pump appeared to function normally and nothing tripped, and the...
As above, if the distribution circuit is installed such that it does not need additional protection against shock, and the sub DB provides such protection to the final circuits that need it, then you can launch from a BS3036 fuse. When calculating the cable size, don't forget the additional...
The manufacturers' instructions have to allow for the situation where a newly qualified installer wishes to fit their component to the highest standard. It might be the first real installation work in their career, with very little experience to guide them on how terminals behave. By providing...
I think the relays in the windlass are unlikely to need more than 4A. If you have a multimeter with a 10A DC current range, use it to measure the current taken through the up and down wires. Simply put the meter probes across the switch, i.e. between the red (common) and either direction. The...
If I understand you right, every circuit individually achieves over 200MΩ but when the neutrals are commoned, one circuit reads 1.4kΩ L-E? Do we know what the aggregate N-E reading was at that moment? You mention bollards; presumably this means permanently-connected lighting loads (on which we...
That is the colloquial way of describing it, yes, but unfortunately it's conceptually back-to-front. The supply provides a voltage (push) and the resistance of the load allows a certain amount of current through. Until the 1950s it was quite standard to refer to voltage or potential difference...
This is what I would call a pathological configuration that is specifically designed to be difficult to analyse in the terms set out in the regs.
An unfused spur on an RFC bypasses the convention Ib<In<Iz due to the downstream protection afforded by the load being a single BS1363 point...
The crux is that to qualify as a safe and compliant unfused spur, as mentioned above it must only serve one point, which is what prevents the cable being overloaded. It doesn't matter whether it comes from the MCB or some other point in the ring.
A 2.5mm² radial connected to a 32A MCB serving...
How long is a piece of string? Yes, insulation resistance can go all over the shop with sheathed elements. I agree with the 0.3MΩ as an attainable limit but it's a bit of a last resort. Good elements that have been baked out should be able to do better than that.
As @timhoward suggests, N-E (or...
Looks like one cable with orange and blue cores paired is from a transformer and one from the push. By linking the blues you cam extend the transformer feed through to where the push was.
Noting that using the 'conversion' method shown in that link, the PL and SL can be connected to L1 and L2 at any switch or paralleled with any run of the 3-core, including at an intermediate or in between two intermediates.
Not applicable to the OP, whose PL and SL are in the same box, but...
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc