Commercial Microwave query, 500V 20A Supply

[skhudy]

Commercial Microwave at business packed up. The only info I can find is it's a 2.9KW Microwave (1800w Microwave power output), and it's hard wired to a small box supply on the wall with a lever cut off which is marked as 500V 20A Supply (put in 40 years ago).

I'm told the supply used to power an older microwave 15 years ago and a food waste disposal unit

I'm happy to get an electrician in to wire up a new Microwave, but unsure what I'm meant to be looking for. I can see commercial microwaves for 1 phase, 2 phase and on a 13amp plug. The 500V supply has thrown me, any idea what I need to look for?

 

[Echo the husky]

The 500V will be the maximum voltage that can be used with the isolator. A common rating for MEM isolators.

The microwave should have a rating plate, the number of wires in the cable should be a give away to the voltage too.

 

[skhudy]

The 500V will be the maximum voltage that can be used with the isolator. A common rating for MEM isolators.

The microwave should have a rating plate, the number of wires in the cable should be a give away to the voltage too.

There is no rating plate like you normally see on an appliance... only info I can find is from looking up the Model Sanyo EM-C2000
circuit diagram is below
https://www.manualslib.com/manual/1167459/Sanyo-Em-C2000.html?page=4#manual

So bit of a quandry, just wanted to get a like for like to make it simle, do I have to get someone in to advise before purchasing - or should I get a similar Micro power one and an electrician can easily do the re-wiring if needed?

 

[333rocky333]

Most commercial microwaves are 1 phase at about 220 volt and run at the limit of a 13 amp plug about 3kw so they just plug in a socket.
The thing marked 500volt sounds like it may an old 3phase supply, though some older metal isolaters were embossed with 500 volt even though they were actually used for 220 volt, either could have been reused to supply your 1 phase unit.
A picture may help.
Its likely its an isolator with no fuses in it, so your microwaves protected by the supply mcb rather than the 13 amp fuse in its existing plug.
An option may be to get a socket outlet PROFESSIONALLY wired into your wall switch and buying a new 1 phase 220volt commercial microwave that simply plugs in.
They are not cheap though.

 

[333rocky333]

At the top of the drawing you posted it says 230v 50 Hz that is 1 phase, the 3 connections show L Live, N Neutral and earth in between