Adding panel and wiring for equipment

[Chris Barnett]

Due to addition of 220-volt 3hp TS and BS, 2 hp lathe, and 5 hp planer, shop needs a subpanel and several new 220 volt outlets. Purchased 8 AWG 3 cond w/ gnd but noticed the power leads on all equipment are all three conductor. Operating manual states to add a separate ground from the equipment to electrical ground, thus making the requirement 3 cond w/ gnd. Seems appropriate to run 4 conductor power line to the equipment instead of having a separate copper wire connected somewhrere on the equipment to ground.
But reading relative posts on 220 volt wiring, seems the common approach is to use 2 cond w/ gnd and tie the gnd to the gnd terminal strip for power equipment, perhaps on the assumption the equipment does not use 120 volts anywhere (example: is the numeric display on the PM 3520B 220-volt?). I initially purchased plugs/receptacles having only three conductors, two hot and ground, but since four conductor cable was purchased, I also bought four conductor plugs and receptacles as found for stoves.
I am not sure what the correct or required wiring convention is for this equipment, particularly when having to use stove wiring hardware to obtain two hots, a neutral, and a ground. And the 4 conductor plugs are huge but wiring with 8 gauge would be much easier.

[Rollie Meyers]

Unless you have 120 volt items in your equipment, all you need is 3 conductors for 240 volt equipment, Line, Line, & equipment grounding conductor....

[Steve Juris]

If the equipment is 220/120 VAC like a lot of hot tubs... 4 wires are needed
I know that hot tubs are a bit off topic, but they are common 220/120 products
In this case the pumps/heater are 220 and uses 2 hots and a ground
The controls and accessories are 120 and use 1 hot, a neutral and ground

If the equipment is all 220VAC.... then 3 wire is fine

You are not limited to stove plugs and cords....
In the electrical dept they sell twist lock receptacles and twist lock plugs
They sell them in 3 and 4 conductor versions
Look for something that says L6-15 or L6-20 or L6-30.....
(L means locking 6 means 220VAC and 15 is amperage)

I would buy round rubber "SJ" cord of the correct gauge and make my own tails from the machine to the receptacle.... hardwired on the machine side and a twist lock plug of the correct amperage on the other... this way you can make them any length.... oven whips are I think by code pretty short.

[Chris Barnett]

120 volts might be used for the footbrake on the bandsaw or for speed control/digital readout on the 3520B, but I know of nothing else that might be 120 volt. Did not buy stove pigtails but 4 conductor braided 8 AWG cable to connect equipment to large plug which fits wall socket. Wonder if anyone else has added a separate conductor or strap for ground as suggested by the manufacturer or replaced the furnished equipment cable with a 4 conductor cable?

[Roger Frazee]

Chris

The 3520B comes wired for 220 volts single phase. The pigtail from the equipment is white,black and green. I have on numerous times attempted to get powermatic to catch up to speed on their technical descriptions but to no avail. The lathe has an head stock inverter which will allow you to operate it either 3 phase or single phase. As said it comes wired single phase new out of the crate.

The manufacturer lists the motor single phase 6.2 amp 2 hp. At anyrate you need 6-15P (plug) and 6-15R (receptacle) for single phase cord and plug. As Rollie mentioned two hots and ground connect to the plug and receptacle.

I'm not sure what you mean by adding a ground wire. That shouldn't be required. Can you give more detail or qoute from the manual?

Why the 8 awg cord?