I am looking to lease a warehouse and am interested in the type of power it has. I looked at the disconnect for the electrical panel to figure this out, but it has left me a bit confused. Usually when I look at these boxes, they will say something like "208V 3 Phase Power, 200 Amps" or something. This one has me puzzled. Assuming it's properly labeled is this three phase power or single phase or both? What do these markings mean on the image below? Is it even possible to have both single and 3 phase in the same disconnect? What voltage is this? 240?


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    That's not a service panel. That's a shutoff switch to a piece of equipment. Also, that sign is not the voltage of the service, it's the maximum rated voltage for the switch. Most light switches in your house are rated for 250V. Look elsewhere for the service panel. If you see weird looking sockets, it also helps to take pictures of those. – Harper - Reinstate Monica Dec 31 '17 at 20:59

There is only 1 type of power in the switch but the switch is listed for single phase or 3 phase. Single phase would use 2 of the contacts and 3 phase would use all 3 of the contacts. As far as the voltage it can not be more than 240 v So the power in the warehouse could be any thing below 240 single or 3 phase power. If you looked at the breaker panel this can show if single or 3 phase power (if 3 breakers wide it is 3 phase ) but there are several voltages out there 230 v 3 phase was popular many years ago, today 208 is more common.

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    It could also be 277V and he's just overloading the box. We just can't tell anything from here. – Harper - Reinstate Monica Dec 31 '17 at 21:00
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    No 277/480 this switch would not be legal. – Ed Beal Jan 1 '18 at 1:02

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