DIY Doctor UK DIY Forums

Dear all,

One of my kitchen spotlights recently blew, fusing the bulb onto the connection. This meant I had to cut the wires to replace the bulb. I simply twisted the wires together with the new connection, and sealed with electrical tape. However, a few weeks later, the bulb went again. When I had a look at the wires, the electrical tape had melted to such an extent that it was black & burnt.

So, I tried connecting the wires with a terminal block instead (the metal type encased in plastic with screws to hold both wires in place). I tested it by turning the light on with the light hanging from the ceiling, & all seemed fine (ie the terminal block was not hot & the light worked). However, when I tested it with the light installed correctly in the celing (for just 30 mins), the plastic shell of the terminal block had started to melt. It seems the heat from the light in this enclosed space is so intense it will melt plastic.

My question is - is it safe to simply cut off the plastic from the terminal block (so its just the metal part left), or is that dangerous? Alternatively, does anyone know where to get small heat resistant terminal blocks from (where you dont need to buy 5000 of them!).

Many thanks

Grubby

[quote="Grubby"]Dear all,

One of my kitchen spotlights recently blew, fusing the bulb onto the connection. This meant I had to cut the wires to replace the bulb. I simply twisted the wires together with the new connection, and sealed with electrical tape. However, a few weeks later, the bulb went again. When I had a look at the wires, the electrical tape had melted to such an extent that it was black & burnt.

So, I tried connecting the wires with a terminal block instead (the metal type encased in plastic with screws to hold both wires in place). I tested it by turning the light on with the light hanging from the ceiling, & all seemed fine (ie the terminal block was not hot & the light worked). However, when I tested it with the light installed correctly in the celing (for just 30 mins), the plastic shell of the terminal block had started to melt. It seems the heat from the light in this enclosed space is so intense it will melt plastic.

My question is - is it safe to simply cut off the plastic from the terminal block (so its just the metal part left), or is that dangerous? Alternatively, does anyone know where to get small heat resistant terminal blocks from (where you dont need to buy 5000 of them!).

Many thanks

Grubby[/quote]

GRUBBY

Obviously after isolating circuit , and making sure the power
is off , it could be that the wire is situated too close to the
lamp and needs to be of heatproof variety.
Go to your nearest electrical wholesaler , and ask about
heat resistant connectors available , as wall as cable , and
heat resistant sleeving which can also be purchased .

BLAKEY1963

[quote]This meant I had to cut the wires to replace the bulb[/quote]
So I am guessing you have a 12 volt bulb and instead of using a lamp holder you have clamped the wires onto the bulb pins? Since the plugs with wires are interchangeable you could buy any cheap lamp and use the socket at less than £4 if on the other hand you still have the sockets and want to connect the two sets of wires then porcelain connectors cost 23p but what about feed wires they are also PVC?
Eric

not quite - there is a little round plastic connector that came with the bulb (the original one got permanently attached onto the bulb that blew!). This is what the bulb connects to, and there are 2 wires coming out the back of it.

So, in order to connect this new bulb (with plastic connector) to the existing wires I had to cut the old bulb & connector off - meaning I have to connect the old & new wires together. And because the heat is so intense, I'm having trouble finding a connection method that doesnt melt

porcelain connectors cost 23p their number 27980-89 but not shown in on line version of their catalog I am sure you will get same thing in any electrical whole sale outlet. Should be OK for about 300degC.
Eric