grounding and bonding a 5,000 amp servoce 2005 nec

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grumpy11

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ok here we go one 277/480 volt service with three service switches.
copper detail through two enclosure .
neutral has a gec connected to it.
service switches just connected to all four copper details.
not one service switch is bonded ,
i say all three have to be bonded
how am i doing so far
 
Are you saying there are three sets of conductors from the utility pole to three parallel switches?

A sketch could be helpful.
 
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grounding 5,000 amp service

grounding 5,000 amp service

yes but its more like 10 set to parelle detail
 
what is it that you want to bond? The disconnect enclosure? The conduit with the service conductors in it? the conduit with the GEC in it?
 
grumpy11 said:
ok here we go one 277/480 volt service with three service switches.
copper detail through two enclosure .
neutral has a gec connected to it.
service switches just connected to all four copper details.
not one service switch is bonded ,
i say all three have to be bonded
how am i doing so far
Click to expand...

If the GEC is bonded to the grounded(neutral) buss and the switches are all connected to that, why would they need an additional bond? Is the GEC sized to the combined total size of all 10 parallel runs?
 
Are all switches in the same enclosure and connected to same bus?

Is it suitable for use as service equipment? If so it should have some means of bonding. If not you need to bond the neutral to the enclosure with a conductor sized according to 250.66.
 
grounding of service

grounding of service

got one 4/0 going to neutral bar ground bar from neutral going to frame of cabinet. two other cabinet are bolted togeter to this.equipment grond bar connecting all three cabinets. with no electrical connection to anything.
all three switches are connected to detail going through all three cabinets
the neutral is connected to all switches but the neutrals not bonded
as per 250.24 c
 
So you're looking for the main bonding jumper? In my experience with equipment this size it should be a piece of bus that bolts the neutral directly to the frame of the equipment. The EGC bus isn't required to be connected to anything but the metal frame of the equipment once the MBJ is in place.
 
grumpy11 said:
got one 4/0 going to neutral bar ground bar from neutral going to frame of cabinet. two other cabinet are bolted togeter to this.equipment grond bar connecting all three cabinets. with no electrical connection to anything.
all three switches are connected to detail going through all three cabinets
the neutral is connected to all switches but the neutrals not bonded
as per 250.24 c
Click to expand...


Bolts holding them together is an electrical connection. It is probably listed to be used this way also. This is not the same thing as bolting three listed "stand alone" disconnects together. The thing is a unit possibly designed to be field assembled and could be customizeable with different modules but whatever is assembled is a complete system or unit.
 
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