Sizing service entrance cable

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Dansos

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Hey guys I’m sure there is a thread on this but I can’t find one. We are installing a service on a commercial building and the llord wants 4 200A Meters installed. The meter stack we are using Schneider MPH64200 has factory dual lugs that accommodate up to (2) 600 AL. They do not make anything bigger then that for their meter packs. They informed me that their buss is only rated for 600A and that is why they do not make bigger lugs then that. We sized the service for 700AL x 2 but now after talking with them, I’m a little lost on how we should go about sizing these cables. I feel this is a similar situation to a 320A meter with (2) 200A Panels ran off it…… but I could be wrong and I don’t want to be wrong with this one lol. Should we size these cables based on the busses of this meter ?? Any input would be appreciated. Thank you
 
You need to use your load calculation for the total load on the four service disconnects to size the service entrance conductors to the meter stack. You would not use 4*200 as the basis for sizing the SEC's. If the total calculated load were 300 amps you could use 300 amp conductors to feeder the meter stack.
 
infinity said:
You need to use your load calculation for the total load on the four service disconnects to size the service entrance conductors to the meter stack. You would not use 4*200 as the basis for sizing the SEC's. If the total calculated load were 300 amps you could use 300 amp conductors to feeder the meter stack.
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Ok thank you. We have done that in the past when we had prints for the job. These are vacant now so how would we go about figuring out loads for each unit ?
 
Dansos said:
Ok thank you. We have done that in the past when we had prints for the job. These are vacant now so how would we go about figuring out loads for each unit ?
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Good question I'm unsure if Article 220 will be of any help with unknown future loads (maybe someone else will chime in). Since the bus in the meter stack is rated for 600 amps then using 600 amps worth of service entrance conductors would work for any future loading.
 
Even if they are vacant you could make a relative accurate load calculation. Assuming the HVAC is set and, from the wiring, you should know if the plan is for electric or gas appliances, etc.
 
Not sure how your inspectors are there, but I am pretty "libertarian" on changing and using whatever lugs suit me on equipment like this and here the inspectors don't notice and or don't care. If I am reading that correctly they do not provide a factory option for two 500s. You could use some off-the-shelf double 500 lugs if you think no one will care, or if you want to go with the factory options looks like you would have to go with three sets. Three sets of 250 would be a little under 600 if it's in a common riser, 300 would get you a full 600 in a common riser.
 
The OP says "has factory dual lugs that accommodate up to (2) 600 AL" so I don't an issue with using 2 sets to get the 600 amps.
 
Thanks for all the input guys. I’m going to plan to just drop 600A cables and call it a day. Just wanted to throw it out there for you guys that do larger projects like this. Thanks again !!
 
If their buss is rated for 600 amp this won't really help but at one time they made "mack adapters" (or something like that) that would allow a bigger size wire, with the adapter, to connect to a smaller size lug.
 
Sorry for the second pic.
I meant to post up a pad kit and then double barrel 750 mcm lug.
Using the pad kit eliminates the factory lugs and allows you to use a double barrel larger lug for the 700.
Again sorry
 

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Something like this.
You could also use a four hole and go with four sets 250. And or other configurations. Check with square D rep on what they can supply with the pad kit. Pad kits are cheap.
I do believe the unit is not continuous duty rated so there is the reason for the 600 amp buss. Using this for a commerical set up I would consider this continuous duty rating into applicable allowable load per unit. Since your land lord has no load sheet I would provide them with a maximum load per unit. I would look into the 80% rating per service disconnect or 160 amps per unit. With demand factors for each units load you should be ok.
 

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I would also like add just in case. If you land lord needs four meter for four units. You may want to ask about a house meter. If on is a house meter reduce to a 125 amp handle for that unit. If four plus house go to five meter and get the 800amp continuous duty rated buss.
In our area a house meter is required.
 
infinity said:
The OP says "has factory dual lugs that accommodate up to (2) 600 AL" so I don't an issue with using 2 sets to get the 600 amps.
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You can often have whatever lugs you want put on by your switchgear specialist. Less work in the field

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infinity said:
Good question I'm unsure if Article 220 will be of any help with unknown future loads (maybe someone else will chime in). Since the bus in the meter stack is rated for 600 amps then using 600 amps worth of service entrance conductors would work for any future loading.
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Usually future loads are not a huge consideration in a multiplex. Not going to be putting an addition on an apartment. We've always calculated to the tee, with maybe a few extra amps.

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