Old code Hospital Ground Fault

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1987 NEC this is found under

B. Wiring Systems- General

517.14 (there is no 517.17) Groung fault Protection

(a) Feeders. When ground-fault protection is provided for operation of the service disconnecting means, an additional step of ground-fault protection shall be provided in the next level of feeder downstream toward the load.Such protection shall consist of overcurrent devices and current transformers or other equivalent protective equipment which shall cause the feeder disconnecting devices to open.

(b) Slectivity. Ground-fault protection for operation of the service and feeder disconnecting means shall be fully selective such that the feeder device and not the service device shall open on geround-faults on the load side of the feeder device. A six cycle minimum seperation between the service and feeder ground-fault tripping bands shall be provided.

Operation time of the disconnecting devices shall be considered in selecting the time spread between these two bands to achieve 100 percent selectivity

(FPN) See section 230-95 Fine Print Note, for transfer of alternate source where ground-fault protection is applied

(c) Testing When equipment ground-fault protection is first installed, each level shall be performance tested to ensure compliance with (b) above.
 
M. D. said:
1987 NEC this is found under

B. Wiring Systems- General

517.14 (there is no 517.17) Groung fault Protection

(a) Feeders. When ground-fault protection is provided for operation of the service disconnecting means, an additional step of ground-fault protection shall be provided in the next level of feeder downstream toward the load.Such protection shall consist of overcurrent devices and current transformers or other equivalent protective equipment which shall cause the feeder disconnecting devices to open.

(b) Slectivity. Ground-fault protection for operation of the service and feeder disconnecting means shall be fully selective such that the feeder device and not the service device shall open on geround-faults on the load side of the feeder device. A six cycle minimum seperation between the service and feeder ground-fault tripping bands shall be provided.

Operation time of the disconnecting devices shall be considered in selecting the time spread between these two bands to achieve 100 percent selectivity

(FPN) See section 230-95 Fine Print Note, for transfer of alternate source where ground-fault protection is applied

(c) Testing When equipment ground-fault protection is first installed, each level shall be performance tested to ensure compliance with (b) above.
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Thanks. I actually went to the library and i was looking to see when the later part was enacted exactly.

"(B)Feeders....
The additional levels of ground-fault protection shall NOT be installed as follows:
(1)on the load side of an essential electrical system transfer switch
(2)Between the onsite generating unit described in 517.35(B)
(3) On electrical systems that are not solidly grounded wye "


Do you know what code this part was adopted???? Thanks for the help
 
the 1996 NEC has a line in the margin next to the text you reference,..I think that means it was added in that particular code cycle.
 
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