Not sure if I'm in the right forum here , but if you don't ask, Have made a bedside lamp which i bought a push button switch for in Maplins, its rated at 125Vac at 3A, 250Vac at 1A, and has two prongs, I connected the live going to bulb and live going to plug to one prong and neutrals to other prong, the plug has a 13 amp fuse in , the lamp came on when plugged in but circuit shorted when I pushed the button to turn off, I'm sure the solution is simple but can;t find the answer on the net, cheers
Lamp switch
- Thread starter paulc
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engineer one
Established Member
ok first thought change the fuse to 3 amp. 13 is too way out.
second do you have a circuit testing screwdriver? check that you have
proper live etc.
i assume that the maplins switch has two plastic things which
have screws in them, called connectors. have you made sure the
wire is properly in each.
silly questions i know, but did you remove the coevring properly,
have you wound the wire to make it more solid,
have you pushed the wire into the hole and screwed down properly,
can you pull the wire out of the hole??
each of these can cause a short. course the other problem could be
a dumb switch.
final thought, areyou sure that the light fitting does not need a
separate earth? normally there is something else which needs
earthing.
hope some of this helps
paul :wink:
second do you have a circuit testing screwdriver? check that you have
proper live etc.
i assume that the maplins switch has two plastic things which
have screws in them, called connectors. have you made sure the
wire is properly in each.
silly questions i know, but did you remove the coevring properly,
have you wound the wire to make it more solid,
have you pushed the wire into the hole and screwed down properly,
can you pull the wire out of the hole??
each of these can cause a short. course the other problem could be
a dumb switch.
final thought, areyou sure that the light fitting does not need a
separate earth? normally there is something else which needs
earthing.
hope some of this helps
paul :wink:
Will change plug to 3 amp , cheers, no connectors with screws , but my soldering was fairly dodgy, fitting is plastic with only two connectors so i don't think/hope it doesn't need earthing ?, the plug says 13amp/250v so i thought id leave in the fuse, do lamps always take 3amp fuses ? Why would a 13amp fuse in plug cause a short in this case? Thanks for your help, its hard to find specific answers in books or on the net.
engineer one
Established Member
ok, not suggesting the connector need earthing, but the light fitting
might well see whether there is an extra screw thing at the bottom
of the light fitting just above the threaded portion where the wires come
in.
basic lesson in electrics, almost ALL small equipment needs less than 13 amp in the fuse, even many tv's, hi fi's, radios etc
formula is watts/volts equals amps from memory.
because of the eu rule about plugs wired onto equipment these days, too many people overload their circuits by not de rating the plug.
think about this logically, if there is something wrong with the appliance,
then you want it to fail as near to the plug as possible, not at the main
box where getting there could be a hot wire that might set light to furnishings etc. about the only things in my house that have 13 amp fuses
are the fridge, freezer, and washing machine. even the microwave is only 5 amps.
mind you my router has a 13 amp one but it is 2000 watts. see how it works??
make sure your check your solder joints again.
finally, are you sure you checked the wiring notice that came with the
connector, and have you connected the plug wires properly??? :?
hope that helps
paul :wink:
might well see whether there is an extra screw thing at the bottom
of the light fitting just above the threaded portion where the wires come
in.
basic lesson in electrics, almost ALL small equipment needs less than 13 amp in the fuse, even many tv's, hi fi's, radios etc
formula is watts/volts equals amps from memory.
because of the eu rule about plugs wired onto equipment these days, too many people overload their circuits by not de rating the plug.
think about this logically, if there is something wrong with the appliance,
then you want it to fail as near to the plug as possible, not at the main
box where getting there could be a hot wire that might set light to furnishings etc. about the only things in my house that have 13 amp fuses
are the fridge, freezer, and washing machine. even the microwave is only 5 amps.
mind you my router has a 13 amp one but it is 2000 watts. see how it works??
make sure your check your solder joints again.
finally, are you sure you checked the wiring notice that came with the
connector, and have you connected the plug wires properly??? :?
hope that helps
paul :wink:
DaveL
Established Member
Hi Paul,
If the switch only has two connections on it you should wire it in series with the lamp. So live wire from the plug to the switch, other switch connection goes to one side of the lamp. Neutral wire from the plug goes to the other connection on the lamp. If the lamp holder is metal then it should have an earth connection to it, plastic ones don't have this.
The fuse is there to stop the cable melting if a fault developes, all of the standard plugs sold in the UK are 13 amp, but for small equipment like lamps the wire will only be rated at 3 or 4 amps, the lamp will only draw 1 or 2 amps at most, unless its a very large spot or flood lamp. All of the fuses for the plugs are the same physical size, they just have different rated fuse wire inside them.
If the switch only has two connections on it you should wire it in series with the lamp. So live wire from the plug to the switch, other switch connection goes to one side of the lamp. Neutral wire from the plug goes to the other connection on the lamp. If the lamp holder is metal then it should have an earth connection to it, plastic ones don't have this.
The fuse is there to stop the cable melting if a fault developes, all of the standard plugs sold in the UK are 13 amp, but for small equipment like lamps the wire will only be rated at 3 or 4 amps, the lamp will only draw 1 or 2 amps at most, unless its a very large spot or flood lamp. All of the fuses for the plugs are the same physical size, they just have different rated fuse wire inside them.
It doesn't sound to me like you have the right kind of switch. It should have four terminals - neutral in, neutral out, live in and live out.
edit: or what Dave said about just switching the live.
With two terminals, it sounds as if you are switching the live to connect to the neutral, so not surprising that the circuit breaker is objecting.
Do you know the part number at Maplin?
edit: or what Dave said about just switching the live.
With two terminals, it sounds as if you are switching the live to connect to the neutral, so not surprising that the circuit breaker is objecting.
Do you know the part number at Maplin?
Plenty of in line switches only have two terminals.
The usual way is to run the neutral straight from the plug top to the lamp holder without cutting. The live goes from plug to one terminal on the switch and another live from the switch to the lampholder. Take care when stripping the outer insulation from mid way along the flex so as not too damage the inner insulation.
The switch will then break or make the live wire thus making or breaking the circuit.
If you are fitting an earth then this should also run straight from the plug top to the lampholder.
Jason
The usual way is to run the neutral straight from the plug top to the lamp holder without cutting. The live goes from plug to one terminal on the switch and another live from the switch to the lampholder. Take care when stripping the outer insulation from mid way along the flex so as not too damage the inner insulation.
The switch will then break or make the live wire thus making or breaking the circuit.
If you are fitting an earth then this should also run straight from the plug top to the lampholder.
Jason
davy_owen_88
Established Member
As DaveL says, the switch is probably only there to switch on/off the live. So you need live from the plug into one terminal and then from the other terminal to the live at the lamp. The neutral cable should be connected straight from the plug to the lamp. And an earth is needed if there are any metal parts that could become live if a wire becomes detached.
As paul describes his wiring when the switch is in the off (open) position both live & neutral are unbroken so the lamp lights. When the switch is in the on (closed) positing there is a dead short between live & neutral.
Top is as pauls, bottom is correct though colours should be brown - live and blue - neutral and not red-live, black neutral
Jason
Top is as pauls, bottom is correct though colours should be brown - live and blue - neutral and not red-live, black neutral
Jason
engineer one
Established Member
maybe you could let us know what kind of switch it is from mapliens.
do you have a catalogue number for instance, then we could
check whether our advice makes sense.
paul :wink:
do you have a catalogue number for instance, then we could
check whether our advice makes sense.
paul :wink:
engineer one
Established Member
my first impression is that this is a switch that ought only to be
connected to one wire, but surely there is a spec sheet?
looking further i would have thought FH94C would be a better
product.
although personally, i prefer slider, or tip switches which have
two wire connections, and are more positive and safer in my
personal opinion. i like to be sure that the two wires coming from the
plug actually connect and are both broken through the switch.
belt and braces for me with electricity, i still read the labels
when i buy new plugs to ensure i wire correctly.
be safe
paul :wink:
connected to one wire, but surely there is a spec sheet?
looking further i would have thought FH94C would be a better
product.
although personally, i prefer slider, or tip switches which have
two wire connections, and are more positive and safer in my
personal opinion. i like to be sure that the two wires coming from the
plug actually connect and are both broken through the switch.
belt and braces for me with electricity, i still read the labels
when i buy new plugs to ensure i wire correctly.
be safe
paul :wink:
