3-phase: how to tell amperage/voltage?

Hi,

After an 8-month-long search, I may finally have found a space on campus for a forge.

For my forge I want a hydraulic press, which = power hungry

The room is shared by a bridgeport mill, a lathe, and a metal bandsaw, which I'm told run on 3-phase.

I'm new to this. I know that with standard household power, all outlets are 15amp, unless one contact is turned 90 degrees, and then you know it's 20amps.

I'll visit the shop again tomorrow or tuesday and examine it more closely. How do I tell the voltage and amperage of this 3-phase circuit, so I know how much I can load onto it? The press would benefit from a 5-10 hp motor, so I need to know if it could handle that power. How do I find out; are there specific plug types to recognize-- if you even use plugs?

thanks! -Bernard Arnest

Reply to
Bernard Arnest
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A three phase plug is usually a twist plug with 4 prongs.

Also look at the motor data plates on the machine tools. They will tell you the voltage and if it is single or 3 phase.

Also if it is on campus they probably have an electrician on staff and you could ask him. You might need a dedicated circuit.

Reply to
Roger Shoaf

First of all you really need an electrician to look at the room wiring. I don't want to apear insulting but if you don't know about electrics, get a professional in. Do the other room users know you want to put a forge in there? The forges I've seen (which is relatively few) make lots of nasty black dust which lathes etc don't like.

Reply to
John

You really can't tell much from the plugs in the room, there is enough variation that is will be misleading. This variation is a function of both local intereptations of NEC as well as conventions used by that building.

For a very ROUGH approximation, Bridgeports typicaly come with 2 hp 3 phase motors, ditto for a 15" lathe (less and single for smaller 10" lathe) and 1 hp for a bandsaw (single or 3 phase. This collection of machines totals around 5 hp of load. Room wiring could be anything larger than that. Ask the facilities people to meet you in the room, they can tell you in a couple of minutes what is possible. Be prepared to need a rewiring job to run a new wire from a convient breaker panel to your location through (hopefully) an existing conduit. On campus, this will likely cost as much as the machine you plan to hook up. :(

Your press will not be a welcome neighbor to the machine tools. The dirt will bother the machines, the noise will bother the users.

Bernard Arnest wrote:

Reply to
RoyJ

will bother the machines, the noise will bother the users.>

Most small hydraulic pumps are not much different from small mills or lathes when it comes to noise. An air hammer now would be a different story. Perhaps you meant a coal forge was dirtier? You could always use a gas fired forge which, again, is not all that objectionable.

dennis in nca

Reply to
rigger

thanks for the help! I emailed facilities this morning, and await their response.

thanks again, -Bernard

Reply to
Bernard Arnest

Machines like that and yours don't plug into the wall. They get wired directly into the power panel or into a power switch box that then goes to the panel.

By all means contact facilities before they put you into the forge!!!

Martin

Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member

Bernard Arnest wrote:

Reply to
Martin H. Eastburn

If you want to know the amperage of existing circuits, find the curcuit breaker and read the label on the handle. If they have the place wired for plug-ins, then unplug the machine and read the voltage and current rating that is molded into the outlet.

If you want to know the remaining available capacity in that room, that is a lot harder, and for the most part will require a visit from the local electrician. There may be spare breakers installed in the panel that don't go anywhere, so adding up the existing breakers could give you the impression it is all used up already, when there is still capacity left over.

Jon

Reply to
Jon Elson

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