Need power relay

How many Amps does each device draw?

Make your own using a 20 amp definite-purpose contactor with 120 VAC coil:

Is the device at the far end automatic, or is this "requests power" event manually induced? THe usual technique is to replace the switch for the equipment with a DPST switch. (or just put the power supply through another DPST switch, in which case the fan would run anytime the power is available, reguardless of whether it's being used.

Depending on what the "fume generating equipment" is, you probably can't just find a fan of the same current-draw, and put them in series. So the last choice is to use a current-sensing relay like this one:

I second the wood working shop dust collector switch.

Richard, how would he use a VOLTAGE operated relay to do what he wants to do?

He needs a CURRENT sensing relay, doesn't he?

Here's a "fancy one" which looks like it'd have enough range and capacity to sense the first unit's current draw and power up the second unit:

Looks to me like that's just a power-strip witha strange configuration.. IOW, if it's on power is available to all three devices, and if it's off, there's no power.

I thought OP was looking for something that would supply power to the other devices only when the primary was actually DRAWING power.

I'd be willing to bet you $50 to the 501C charitiy of the winner's choice that your "Looks to me" is dead wrong, Goedjn.

The link I posted may not work, but going to

If you zoom in on the photo you'll see the top outlet is labeled "power tool" and the bottom two are labled "accessory - accessory".

Plus if you click on and read the "Reviews" you'll see users describing doing what the OP wants to do. The only limitation might be its 15 amp capacity.

Wanna place your bet?

Jeff

Mount contactor inside and outlet box outside of tool cabinet/base. Splice contactor coil in parallel with the tool's switched power. Splice tool's incoming cord power into one side of contactor poles, outlet to the other side. Or, use separate AC circuit for contactor supply if you do not want to load the tool's cord. Now the outlet powers on/off with the tool on/off, but the outlet does not load the tool's switch.

But Richard, that's not what the OP said he wanted. To wit:

"I'm in need of an, um, extension cord that, when power is requested by the attached device, an additional outlet on the box goes live."

Note that it reads "requested by", not "when someone flips the power swith on the tool."

And the OP continues, "The scheme seems infinitely simpler than hooking up wiring to the primary device."

Your suggestion that "hooking up wiring" stuff, right?

Hair splitting an RCH I freely admit, but that's what engineers do for fun, isn't it?

Peace,

Jeff

Right. I told him what he needed, not what he wanted. What engineers do for fun.

Thanks. I finally found one. It seems as if you flip the switch on the switch and power is delivered to the outlets on the box, one of which can be the dust collector.

I want something such that when I turn on device #1, device #2 gets supplied power. I don't want to make an electrical connection directly to device #1.

I saw one done in a serious fashion, for a different but similar application. The person used an old air conditioner contactor, and when he powered up, a transformer got power too, kicked on the contactor.