3 Phase Service Questions

[RegevH]

I have 3 phase 100 amp service that is delta wired (high leg configuration). Out of the meter I have 3 hot wires and a neutral coming out to a 3 phase 100 amp fuse box. From the fuse box I have 3 legs and a neutral running up into a breaker panel that is totally occupied (it only has space for 12 breakers). Running to the left of the fuse box are only 2 hots and a neutral (so there is no 3 phase in the second breaker panel). The above two breaker panels are get their power directly from the fuse box right after the meter, the lug nuts each have two 1 awg wires, except the high leg lug nut that only has one wire running into the upper breaker panel.

I need to install the following:

Table-Saw: 23.4 amp @ 220V 3 phase

Hinge Boring: 6 amps @ 220V 3 phase

Edge Bander: 16 amps @ 220V 3 phase

Line Borer (Future): 16 amps @ 220V 3 phase

Air Compressor: 15 amps @ 220V 1 phase

2 Dust Collectors: 6 amps @ 220V 1 phase X 2 = 12 amps @ 220V

I am figuring that the amps are in the place can do, since the machines will not all be on at the same time, and the existing breaker panels are mostly lights and office outlets.

Questions:
1) What is the difference between a load center and a breaker panel and where would you use each?

2) Can I eliminate the breaker panel to the left of the fuse box and add another 1 awg wire to the high leg lug nut, by replacing it with a bigger breaker panel? Each machinery will be on a dedicated circuit?

3) Can I use a 200 amps breaker panel instead of 100 amps so that if in the future I need to upgrade service, I won't have to do any rewiring?

4) I want to use 10 awg wire (12 awg will do, except for the table saw) and 20 amp breakers for all machines (30 amps breaker for table saw), is this safe?

5) I want to wire the machines with a quick disconnect plug, using SJ wire. Where do I connect the SJ wire ground? Do I connect in to the machine, the junction box, and how is the plug wiring connected? The SJ is running from the junction box to the machine with a quick connect. I am using metal conduit to run the wires to the junction box, so there is no ground wire coming from the panel, but the SJ wire has ground, so do I just connect it to the junction box?

6) Running metal conduit, how many 10 awg wires can I run in 1/2", 3/4" and 1" conduit?

I know this is a lot for a post and I thank anyone who took the time to read this, and even more for replies. :D

[imported_suemarkp]

My questions:

Are your motors labeled 220V, or 230V or 208V? A delta system provides 240V, and should be fine for 230V motors. A motor intended for 208V wye 3 phase may be burned up at 240V.

Your questions:
1) What is the difference between a load center and a breaker panel and where would you use each?

I don't think there is any difference -- to me they mean the same thing.


2) Can I eliminate the breaker panel to the left of the fuse box and add another 1 awg wire to the high leg lug nut, by replacing it with a bigger breaker panel? Each machinery will be on a dedicated circuit?

I don't think you want to do that. I would expect you're going to want some 120V circuits in that building. You really should have a 208/120 or 240/120 single phase panel setup for single phase loads. That way, no one will get the high leg confused and run that to the wrong place. You can use a larger panel if you want since you have a 100A fuse protecting all panels.


3) Can I use a 200 amps breaker panel instead of 100 amps so that if in the future I need to upgrade service, I won't have to do any rewiring?

Yes. You may want to enlarge the 3 phase panel so you have more slots. Since this is delta, using only 2 pole or 3 pole breakers would be a safe thing to do! Only problem you may have is putting in wires large enough to go much over 100A. If the lugs on your fuse panel will take 3/0 copper, then you'll be set for 200A once the fuse panel is replaced and its service feeder upgraded.


4) I want to use 10 awg wire (12 awg will do, except for the table saw) and 20 amp breakers for all machines (30 amps breaker for table saw), is this safe?

Yes.


5) I want to wire the machines with a quick disconnect plug, using SJ wire. Where do I connect the SJ wire ground? Do I connect in to the machine, the junction box, and how is the plug wiring connected? The SJ is running from the junction box to the machine with a quick connect. I am using metal conduit to run the wires to the junction box, so there is no ground wire coming from the panel, but the SJ wire has ground, so do I just connect it to the junction box?

I'm not sure I follow your question. The conduit, if EMT or rigid, is your equipment grounding conductor if things are properly connected (paint scraped, concentric knockous use bonding bushings, etc). Terminating a cord ground to the junction box should be all you need to do.


6) Running metal conduit, how many 10 awg wires can I run in 1/2", 3/4" and 1" conduit?

If you use THHN wire, you can fill with 5, 10, and 16 #10 wires in those respective sizes of EMT conduit. If using the thicker TW or THW-2 wires, fill is limited to 5, 8, and 14 respectively.

[RegevH]

The live wires that are running from the main breaker (fuse box) are 1 awg and since I have 2 breaker panels connected they are pretty tight so I really can't add 3/0 awg to the lugs. Even two 1 awg wires are pretty tight, since there are two panels being fed, so I have to eliminate the panel on the left and use single pole breakers with the new 200 amp panel.

Questions.
1) Out of the top breaker panel, I have two uninsulated grounds coming out, one is going into the nut in the cement floor and the other is going into the meter box. The panel on the left of the main breaker, only has the neutral wire going back into the main breaker. If I change the left panel to a 3 phase 200 amp panel, can I just reuse the same configuration?

2) When using twist lock connectors, do you need a pigtail splice to ground the metal box, that has the 4 wire twist lock connector?

And Mark thanks again

[imported_suemarkp]

You can use the same grounding configuration. The neutral should be doing double duty in a new 200A panel -- it is both the grounded neutral and the equipment grounding conductor.

I haven't seen 3 phase delta panels enough to know if there is positive indications of the high leg bus. You do not ever want to put a single pole breaker on the high leg, as you'll get more than 120V. What you want to do is less safe, but more convenient. You just need to make sure any person adding circuits in the new panel knows what they are doing!

You need to ground your equipment that is cord and plug connected. Just run a green wire from the grounding terminal on the receptacle and attach it the designated ground (if there is one). If no labeled ground, find a good metal connection on the frame and screw the wire to it (use a wire terminal if using stranded wire). This is typically the screw that holds the equipment wire cover in place, but not always.