Thread: Attention electrical guru's

Originally posted by Moses


Never wire pilot lights in series with devices. You will reduce the voltage on all devices. For motors, they could burn out due to overheating.

Anyway, if the pilot lamp blows, then the device in series with it will stop functioning too....

Switching a relay at a reduced voltage causes problems.... okay if you say so.

and same as if the fuse blows... so it won't work either way. [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]

Originally posted by Ralf_the_RR+--><div class='quotetop'>QUOTE(Ralf_the_RR)</div><div class='quotemain'><!--QuoteBegin-Moses


(as an aside, a motor is an electrical device, an engine is a mechanical device. So why are there motorcycles instead of enginecycles? Natural aberation!!)

Answer (from dictionary.com):
1. Something, such as a machine or an engine, that produces or imparts motion.
2. A device that converts any form of energy into mechanical energy, especially an internal-combustion engine or an arrangement of coils and magnets that converts electric current into mechanical power.



So not all motors are electrical. Only electrical motors are.[/b][/quote]

Quite so. I was expressing the terminology from an electronics trades point of view. We don't use electric engines! [img]style_emoticons/<#EMO_DIR#>/tongue.gif[/img]

Originally posted by Hellspawn+--><div class='quotetop'>QUOTE(Hellspawn)</div><div class='quotemain'><!--QuoteBegin-Moses


Never wire pilot lights in series with devices. You will reduce the voltage on all devices. For motors, they could burn out due to overheating.

Anyway, if the pilot lamp blows, then the device in series with it will stop functioning too....

Switching a relay at a reduced voltage causes problems.... okay if you say so.

and same as if the fuse blows... so it won't work either way. [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img][/b][/quote]

If you get 20 12V bulbs and wire them all up in series, they will work on 240V. That's how christmas lights work. And that is why when one blows, none of them work and you have to start at one end and work your way through until you find the dead one, or two, or three....

I can't remember who's law it is, Kirchoff or one of those blokes, that in a series circuit, the current through all devices is the same and the sum of all the voltages across each series component equals the supply voltage.

In a parallel circuit, the voltage is the same across all components and the sum of the current through each component equals the total circuit current.

You could wire a lamp and a fan in series. For a 12V system, the lamp and the fan need to be both 6V devices.

I really don't want to conduct a course in basic DC circuits here.... :wink:

Thanks Drivesafe, i musta had a moment of inspiration [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] as i took power from the fuse box, the relay has a 30 amp blade fuse already mounted so it's all ok.
Moses, i lost ya after "if you get....." [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] seriously though thanks for the advice, the fans working spot on. My wiring knowledge is pretty basic, but i seem to get most stuff to work and i have a large extinguisher [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img]

I don't understand this topic anymore... wiring a pilot light in series with a fan ???????? :? No relay ???

Just make sure you DO use a quality relay for the fan only and if you use a pilot light follow the diagram on the back of the packet. [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]

G'day HS, i don't think my lights wired in series, i think it's in parallel. I've the power wire off the fan to a fused Hella relay, i've got a wire off the solenoid to the relay on the supply side. The relay is earthed to the body, i've got a smaller wire running off the fuse box to one terminal on a standard switch, a wire then runs off the other terminal through the firewall to the switch side of the relay, also running off this terminal is another wire leading to the indicator lamp, and then to earth. Dunno if that's right [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] but it seems to work quite well!