I have a 2,500 kVA, 34.5 kV: 415Y/240V that serves three Crypto-mining containers, each with their own 1,200A Service Panel. I also need to serve (1) standalone, outdoor 5 HP (240V line to neutral) single phase pump. The mining containers are pre-manufactured in China and have no provisions available to add a breaker to their Service Panels. I'd like to serve the pump 240V directly from the transformer secondary. I have a 30A fused combination starter/disconnect that can be mounted near the pump. Since it is a single load, does the Starter/Disconnect enclosure still need to be Service Entrance Rated? I.e. neutral bus bonded? Finding such has been impossible thus far.
Single motor load from Transformer
- Thread starter dball
- Start date
- Status
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Those types of starters are available, try searching for a pumping plant panel, typically used for irrigation...note under the 2020 NEC products may not be available to meet the changes in Art 230
But with your large transformer you will need to calculate available short circuit current and may need a disconnect rated for that
plus with a service rated pump panel there is no way to turn power off to it.
But with your large transformer you will need to calculate available short circuit current and may need a disconnect rated for that
plus with a service rated pump panel there is no way to turn power off to it.
We may end up setting a small SE rated panel or loadcenter upstream from pump, to serve some outdoor lights around each transformer. I would only need a couple of breakers.
In this case, the customer owns the large transformer. The Utility constructed a 34. kV overhead line to serve 20 transformers. There is a 34.5 kV GOAB switch upstream, and fused cutouts at each transformer dip. I suppose technically the Service starts at the cutout, but we have treated each 415Y/240V secondary as a service to the mining enclosures. I.e., the enclosure's 1200A MDP is the Service panel and neutral is bonded there.
In this case, the customer owns the large transformer. The Utility constructed a 34. kV overhead line to serve 20 transformers. There is a 34.5 kV GOAB switch upstream, and fused cutouts at each transformer dip. I suppose technically the Service starts at the cutout, but we have treated each 415Y/240V secondary as a service to the mining enclosures. I.e., the enclosure's 1200A MDP is the Service panel and neutral is bonded there.
Whole different ball game now that you are dealing with SDS rather than utility.
I would question the size of your "on hand" combination starter. 30 amp seems small for a single phase 240v 5 hp motor
I would question the size of your "on hand" combination starter. 30 amp seems small for a single phase 240v 5 hp motor
Although there are several similarities in the manner the NEC looks at services as opposed to customer SD systems including the fact that disconnecting means fed directly from a utility service would need to be "Service Rated" whereas a SDS fed disconnect would not need to be, and
the requirements for 250.30 differ from those in Art 230.
the requirements for 250.30 differ from those in Art 230.
- Status