Transfer Switch Location

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jjdh

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Can someone point me to the NEC code that allows the installation of a "service entrance rated" Transfer Switch between the POCO meter and the main switch.

Is a Main Switch (overcurrent device) required before the Transfer Switch in the POCO service conductors?
 
230.66 requires equipment to be rated

Service equipment rated at 600 volts or less shall be marked to identify it as being suitable for use as service equipment.

230.90 and 91 requires the OCP in series with the service conductor.

Each ungrounded service conductor shall have overload protection.

230.91 Location.
The service overcurrent device shall be an integral part of the service disconnecting means or shall be located immediately adjacent there

Rick
 
NEC 230.83 does not mention transfer switches on the supply side of the service disconnect. I am confused
 
Pierre C Belarge said:
The listing of the product, listed as suitable for services, permits a service rated transfer switch to be installed in such a manner.
110.3(B)
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NEC 230.82 does not mention transfer switches on the supply side of the service disconnect. I,m confused!!
 
jjdh said:
NEC 230.83 does not mention transfer switches on the supply side of the service disconnect. I am confused
Click to expand...

The transfer switch needs to have an over current protection device in it for the service conductors to land in first and it also has to be indicating showing the on or off position.
 
OK meter - tranfer switch - main switch normal power.

Generator - Gen oc ( non seperately derived system) - transfer switch - main switch.

can generator feeders go thru meter?
 
RUWired said:
The transfer switch needs to have an over current protection device in it for the service conductors to land in first and it also has to be indicating showing the on or off position.
Click to expand...

So the transfer switch is the main switch?
230.91 requires oc in main switch or immediately adjacent therto.
I feel safer with this . but is it required?
 
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jjdh said:
OK meter - tranfer switch - main switch normal power.

Generator - Gen oc ( non seperately derived system) - transfer switch - main switch.

can generator feeders go thru meter?
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Should be meter,main,transfer switch. No the generator feeders cannot go through the service conductors meter.
 
RUWired said:
Should be meter,main,transfer switch. No the generator feeders cannot go through the service conductors meter.
Click to expand...

I agree but I can't find code references to enforce it by. also the issue of the generator feeders in the meter I agree with nec 230.7.
 
If the oc is ahead of the ATS, the service conductors (def) stops at the ATS. The Load side is feeder conductors, emergengy,normal and load.

Service meter - main disc external or in ATS.

Feeders
Gen feeder non-seperately derived to ATS emergency
Main switch load feeder to ATS normal
ATS load feeder to non-seperatly derived panels

code reference 230.82

Is this correct?
 
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Maybe this illustration from Mike Holt will help some.

1100707982_2.jpg


This is a transfer switch installed on the secondary side of the service disconnecting means.
If the transfer switch is "service rated", it is permitted as the service disconnecting means, which means the service disconnecting means ahead of the transfer switch in the picture is not necessary/required.
 
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Well heres a fire pump controller we install these on every job it has a main breaker factory installed inside on the right hand side the emergency breaker is on the left hand side this is fed from the poco transformer its service rated this is for the 250 HP fire pump .http://i611.photobucket.com/albums/tt195/stringking/428.jpg

In orlando florida any 480 volt 200 amp or less service only has to have a disconnect before the meter but thats the only case a disco is ahead of a meter.

Thats just a power company rule not NEC .
 
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