Electrical hazards and safety precautions for enclosures.

[froot]

As a result of one of our fellow member's recent experience losing prize animals from an electrical fire, we need to focus on how we do things to prevent such disasters. Feel free to share all your preventative measures, as well as incidents you may have experienced so we can all learn and hopefully avoid such tragedies.

[froot]

A point I made in that topic...

Just a pointer from an observation I have made. I was using a length of standard heating wire, the same that's used in those foil backed heating pads, in a chemistry synthesis to maintain temperature in a bowl of water. The wire was simply coiled up and placed in the water and turned on. It worked very well until it burned out. I discovered that a short occured in 2 places where the coils were touching each other.
The moral of the story is, never let any of your heating wires touch each other, I have heard stories of these heating pads catching fire and this is probably how it happens. Go now to your setups and check this, even in the heating pads themselves, on numerous occasions I have found the wires in the foil pads themselves touching each other.

[Bushviper]

Overloading plugs is also a good way to cause a fire. Make sure the connections are soldered or placed in a connector block and not just twisted together.

[Bushbaby]

And all wiring must be insulated

[Leos r gr8]

Hi
I don't know if this has anything at all to do with this subject but last week I tried to do my own wiring on one of those silver AKWA heaterpads, I didn't wire the the plug properly and when I turned it on sparks flew and the plug glowed orange, on closer inspection the wires in the heaterpad had melted! So I had to throw it away.

Guys, I think that for those of us that are not electricians should call a proffessional or someone who knows what they are doing

[froot]

BV has a very good point - overloading!
This one sneeks up on the unsuspecting keeper as his/her collection steadily grows. Every new enclosure means another plug point, and I'm pretty sure plug points in most of your snake rooms look like a mini substations.
I am guilty as sin with this one, all my lights are on a timer circuit. This poor timer's relay is switching at least about 500 watts of lighting and I keep saying to myself I'll sort it out......when I get a chance. The relay does stick from time to time from contact arcing but I give it a good smack and it works again.
With lighting a problem like this is way more forgiving that a thermostat circuit. Depending on the aggressiveness of the heating element, a thermostat relay that is stuck can really spoil you and your animal's day.
The solution I have for this, which I will be doing with my lighting circuit (when I get a chance), is to use the timer/thermostat relay to operate a bigger more robust relay/contactor. This way, the only load the thermostat will experience is that of the bigger relay's coil, which is minute compared to that of a light bulb. The bigger relay will then switch the main load from the setup with ease.
If you need a circuit diagram or help to select components, let me know.

[Bushbaby]

Which lights are you using? The lights I have in my cages are all energy savers. How much power do they pull?? Any idea?

[froot]

I can't tell you off hand, they vary from infra reds to 12v mini's to oven lights to flourescents. The problem with energy savers is they don't help much in the way of basking lights, but they will work fine where a flourescent works fine, an energy saver is pretty much a tightly packaged flourescent.

[wickets]

Fires are usually caused by "Hot connections". These would include any screw on a plug or connector block that is not screwed tight. One of the culprits here is the so-called "Chocolate" connector blocks. Their screws strip thread easily, and form a "hot" connection. Also, any broken conductor in a heating pad, will arc, and possibly generate a fire. Therefore a pinched heater wire, is far more likely to cause a fire, than two coils touching each other. Another point to watch, is any electrical wire close to an IR lamp or heater. For heating, why not use a transformer and a low voltage heater? At least that way, the high voltage is removed from the animals. I use underground heating cable as used in nurseries for propagating plants. It has an extremely strong inner, and is water proof. Just divide the length by 220, to calculate the length per volt. Now get a suitable transformer for the length you require. Expensive, but I sleep well at night. BTW, never use the elment from an old warm blanket!

[Natal_Black]

Hi froot , When you say short what do you mean ? Basically the copper wire spilt or broke in half at those points? if this is so , this would not cause a fire it would just stop working?

I have tried shortening those heat cables before , they go up in smoke within miliseconds hehe.

Also i have the same cable thats coiled up in a circle touching itself in many many places as it was too long , no shorts - the wire in each cable is different the higher the wattage the stronger the cable , the 25 watt cables are guaranteed against breakage , but the lower wattages are easily broken and not guaranteed this is what they told me...
I see theres a new 36 watt cable that came out ! those must be awesome , always wanted somthing a little stronger..

[gaboon]

http://www.diyvivs.com/articles/article ... basics.htm

[froot]

Apon close inspection the insulation had melted through and the conductors were touching each other. When I found it it was obviously open circuit but that brief moment when they touch is when all hell breaks loose. If the conductors touch, part of the length of the heating wire is basically being closed out of the circuit and the new circuit now has much less resistance and hence much higher current, heating it up and possibly igniting any flammables around it before it blows to open circuit.

[Natal_Black]

Ok sweet ,In that case I have some modification to do this weekend , funny enough where my cabling is potentialy ''dodgy'' is right next to my absolute favourite specimen. eish! sub obtimal.

[Pythonodipsas]

Also I assume if any electrical fault should happen then the circuit breaker should drop and stop all power coming to the fault? Am I correct in asumming this?

[Bushviper]

Never assume because then you make an ASS out of U and ME.

Not all earth leakages trip when you expect them to. If the short is quick often they dont trip and should if it carries on longer.

I have melted my fair share of heating cable by having one part cross over another part and when this is under a carpet then it usually burns a hole in the carpet. I guess I have been lucky till now.