34.5 KV Distribution

[Shoe]

I have a project where a primary-metered 34.5 KV (looped) distribution system is being considered. This will be internal to the facility and feed indoor unit substation transformers for standard building utilization voltages. I've had extensive experience in facilities that use 15kv class systems and below, but are there any additional things to be aware of when dealing with 34.5 KV systems as it pertains to facility operations and maintenance?

At a minimum, my thought is to physically separate the medium voltage substation/switching and the low-voltage gear, rather than keeping them in a single switchgear line-up. Substations likely to be dry-type but may opt for low-flammability oil-filled.

Any thoughts pertaining to 34.5kv systems and facility operations?

Thanks.

 

[Shoe]

I have a project where a primary-metered 34.5 KV (looped) distribution system is being considered. This will be internal to the facility and feed indoor unit substation transformers for standard building utilization voltages. I've had extensive experience in facilities that use 15kv class systems and below, but are there any additional things to be aware of when dealing with 34.5 KV systems as it pertains to facility operations and maintenance?

At a minimum, my thought is to physically separate the medium voltage substation/switching and the low-voltage gear, rather than keeping them in a single switchgear line-up. Substations likely to be dry-type but may opt for low-flammability oil-filled.

Any thoughts pertaining to 34.5kv systems and facility operations?

Thanks.

Should mentioned circuit protection is fuses.

 

[jim dungar]

If you are going to seperate your transformer and secondary gear, make the divison after the secondary protective device. The arc flash incident energy at the secondary equipment might be reduced by having a 'remote main'.

Are you using primary side breakers or switches?

 

[Shoe]

Good point. Thanks.

Primary side protection is switches with fuses.

 

[jimmac49]

I have a project where a primary-metered 34.5 KV (looped) distribution system is being considered. This will be internal to the facility and feed indoor unit substation transformers for standard building utilization voltages. I've had extensive experience in facilities that use 15kv class systems and below, but are there any additional things to be aware of when dealing with 34.5 KV systems as it pertains to facility operations and maintenance?

At a minimum, my thought is to physically separate the medium voltage substation/switching and the low-voltage gear, rather than keeping them in a single switchgear line-up. Substations likely to be dry-type but may opt for low-flammability oil-filled.

Any thoughts pertaining to 34.5kv systems and facility operations?

Thanks.

Electrical clearances come to mind. Make certain that PPE, testers, etc, are rated for the voltage class. You may want to consider epoxy cast coil transformers..

Jim