pelco housings and electrical safety

[kensplace 0]

Picked up a couple of pelco housings second hand, huge massive beasts they are (I can even fit in the 1 foot long 350mm lens + camera inside it, and still have room at the sides for other stuff...)

 

Cant make out the model number, looks like eh55 something something.

 

They are made out of aluminium, with a gas strut for lid opening closing, and are very, very solidly built.

 

What concerns me, is they are marked as mains (220v) and have 2 heater resistors near the front, which are connected via fairly thin wire, and whats worse, is there is no earthing on the case whatsoever.

 

There are nice live and nuetral wires, which go into a terminal block at the rear, then through a thermistor of some sorts for temp control (well one of the housings has the thermistor, the other does not) and then out to those thin white wires to the resistors that heat up.

 

They work, but is it normal for a pelco case like that to not have a earth? Especially with thin wires for the mains, which pass right over those resistors which can get hot.....

 

Seems like a death trap waiting to happen, are these how the cases are made, or has some idiot modified them in the past? All it would take is for a wire to be damaged, or for the insulation to melt, and the entire case could become 'live' - and they are not even fused inside the case. Course the fuse in the mains plug would blow, but thats not the point....

 

Will end up having to put in 12 or 24v heaters due to the stupid part P regs in the UK anyways, but curious as to whats normal on a large pro pelco housing.

[edit]ps even if its normal, I would still not use it as it is, without earthing/fusing/improving wiring first, if I could do mains, but the uk sucks for diy work these days, nanny state we live in now...[/edit]

[jisaac 0]

....., is there is no earthing on the case whatsoever.

 

 

......All it would take is for a wire to be damaged, or for the insulation to melt, and the entire case could become 'live' - ..................

 

You kind of answered your question in your question

 

The reason also there is no earthing is to prevent your housing from becoming a second ground for the camera itself.

[Cooperman 0]

Hi kensplace,

 

It would be relatively easy to install earthing points (one for the main case, and one for the cover) using threaded bolts, nuts and shakeproof washers (perhaps M6) and earthing wire soldered to some terminals.

 

Without the earthing connection, if the insulation failed and the case became live, then the fuse in the mains plug probably wouldn't blow (unless the person or whatever touching it, created a mains path ).

 

It may be better to fit a low voltage resistor anyway, or possibly a small fan, particularly as the amount of damp air inside such a large housing, will invariably hold a lot of moisture which would just love to condense on the housing window (given half a chance).

[MisterNetwork 0]

Truth is... that is exactly the way they were made. Housings from Pelco & Vicon were all made that way in the 1980s. Pelco's were all metal, Vicon had fiberglass and metal with aluminum sun-shields, but the heaters were crude, and the connections not very installer friendly or safe by todays standards and everything was usually 110 or 24vac.