cinematechnic
Cast Iron
- Joined
- Apr 11, 2005
- Location
- Walnut Creek, CA
After seven years of being in Los Angeles, and after another year of having my machine tools in storage, I will be able to set up shop in a good location (FINALLY).
I’ve already been in business by myself for nearly a year, just barely managing to get by without the use of these tools (like having one arm tied back). So I’m really looking forward to being set up properly.
I would like some advice for the very knowledgable members on this forum regarding how I should set up power in my shop:
The supply to the building is 480V 3 phase. There are three 480:208V transformers in the building. Two 75 KVA in the electrical room (SW corner of building), and one 112.5 KVA in the room where my machine shop will be situated (SE corner).
In the room I will be setting up my machines (we’ll call it the machine room) there are two 200A Siemens panels fed from that transformer. One is set up for mostly single phase loads. The other is set up for 3 phase loads but does not have any 3Ph loads connected. Both have plenty of space available for additional circuits.
Here’s where it gets interesting: There is a ground rod driven into the floor in the corner of my room. The transformer is grounded to that. Also connected to it is a long strip of copper, about 3/4 by 1/4 that runs for half the inside perimeter of the building. Apparently there were building equipment in there thaw was static sensitive so it’s a low-resistance ground.
I took a look inside the panel that I would be connecting my 3 phase loads to (initially there will be only one). It has the three power lines, plus neutral, but no ground. The ground and neutral bars are bonded together and being used as neutral.
Regrettably I must add: Funds are very tight and I have to fund anything special to my needs myself. So I have to choose the least costly path that is safe and that gets me working and making money. There is always the possibility of upgrading the setup in the future.
Questions:
1) Should I be concerned there is not a dedicated ground on the panel I will connect my 3 phase load (2hp Schaublin Lathe) to? I’m assuming the conduit and case of the panel are ground. Does it matter that I intend to add an inverter drive to my lathe?
2) The company I’m partnered with that signed the lease and is paying for most of the renovation wants to remove the copper strip to turn it in for recycling value. I told them I want to keep the strip in my rooms, and I have my own ground rod.
But the strip also connects to the grounding in the electrical room. Will there be any issues caused by breaking that connection? Should we at least run a ground wire to replace the copper strip?
3) My Schaublin has a 380V 50 Hz motor. For now I plan to use a 208V 3 Ph input and the machine’s built-in step up transformer. But I’ve wondered about the possibility of eventually powering the inverter I plan to add (a 460V GE unit) from the 480V power. But I don’t know how to properly set that up.
I imagine that the 480V power could be accessed at the point it enters the transformer case. But would that require another panel box or other requirements?
FWIW - there is a 5HP Ingersoll-Rand air compressor thats 460V 3 Ph in the electrical room. It appears to be connected to the 480V power as it enters the building, in box mounted ahead of the transformers.
ALSO: If anyone that reads this is in Burbank/Glendale CA area and knows a electrician that could do the work for me for reasonable cost, please let me know. At this point I would just need a single 3 Ph outlet connected, close to the panel, and maybe two 208V single phase outlets in the room.
And if anyone can give me an idea of what a very straightforward job of setting up a single 3 ph outlet and one or two single phase outlets, please let me know. It's important to have some perspective on cost.
Thanks in advance for your advice!
I’ve already been in business by myself for nearly a year, just barely managing to get by without the use of these tools (like having one arm tied back). So I’m really looking forward to being set up properly.
I would like some advice for the very knowledgable members on this forum regarding how I should set up power in my shop:
The supply to the building is 480V 3 phase. There are three 480:208V transformers in the building. Two 75 KVA in the electrical room (SW corner of building), and one 112.5 KVA in the room where my machine shop will be situated (SE corner).
In the room I will be setting up my machines (we’ll call it the machine room) there are two 200A Siemens panels fed from that transformer. One is set up for mostly single phase loads. The other is set up for 3 phase loads but does not have any 3Ph loads connected. Both have plenty of space available for additional circuits.
Here’s where it gets interesting: There is a ground rod driven into the floor in the corner of my room. The transformer is grounded to that. Also connected to it is a long strip of copper, about 3/4 by 1/4 that runs for half the inside perimeter of the building. Apparently there were building equipment in there thaw was static sensitive so it’s a low-resistance ground.
I took a look inside the panel that I would be connecting my 3 phase loads to (initially there will be only one). It has the three power lines, plus neutral, but no ground. The ground and neutral bars are bonded together and being used as neutral.
Regrettably I must add: Funds are very tight and I have to fund anything special to my needs myself. So I have to choose the least costly path that is safe and that gets me working and making money. There is always the possibility of upgrading the setup in the future.
Questions:
1) Should I be concerned there is not a dedicated ground on the panel I will connect my 3 phase load (2hp Schaublin Lathe) to? I’m assuming the conduit and case of the panel are ground. Does it matter that I intend to add an inverter drive to my lathe?
2) The company I’m partnered with that signed the lease and is paying for most of the renovation wants to remove the copper strip to turn it in for recycling value. I told them I want to keep the strip in my rooms, and I have my own ground rod.
But the strip also connects to the grounding in the electrical room. Will there be any issues caused by breaking that connection? Should we at least run a ground wire to replace the copper strip?
3) My Schaublin has a 380V 50 Hz motor. For now I plan to use a 208V 3 Ph input and the machine’s built-in step up transformer. But I’ve wondered about the possibility of eventually powering the inverter I plan to add (a 460V GE unit) from the 480V power. But I don’t know how to properly set that up.
I imagine that the 480V power could be accessed at the point it enters the transformer case. But would that require another panel box or other requirements?
FWIW - there is a 5HP Ingersoll-Rand air compressor thats 460V 3 Ph in the electrical room. It appears to be connected to the 480V power as it enters the building, in box mounted ahead of the transformers.
ALSO: If anyone that reads this is in Burbank/Glendale CA area and knows a electrician that could do the work for me for reasonable cost, please let me know. At this point I would just need a single 3 Ph outlet connected, close to the panel, and maybe two 208V single phase outlets in the room.
And if anyone can give me an idea of what a very straightforward job of setting up a single 3 ph outlet and one or two single phase outlets, please let me know. It's important to have some perspective on cost.
Thanks in advance for your advice!