Transformer remote control
Transformer remote control
(OP)
There is a discussion going on in regards to whether or not we needs to add a remote control ( PLC start/ stop through 4.16KV Contactor) to the transformer ( 2MVA 4.16KV/600V).One of concerns from one of our electrical guys is the safety. There is a 600V circuit breaker on the sencodnary of the transformer. In my opinion, there should not be any issues as long as no motors would be truned on automatilly after the energization of the tranformer. Moreover, all the maintenance perosonnel will be protected by the arc flash protection schemes. I would appreciate it if anybody can shed some light on me.






RE: Transformer remote control
How do you start the transformer now? If it is the pushbutton on front of the 4.16KV contactor cabinet, then I would think a remote control would be safer. As well, if the electricians are concerned that someone may remotely start the transformer while they are performing maintenance, this would be prevented if they followed common lock-out procedures.
If you give more detail about your situation, I am sure that someone here can offer good suggestions.
RE: Transformer remote control
RE: Transformer remote control
RE: Transformer remote control
RE: Transformer remote control
Do the concerns from the electricians about safety come from the existing system or are they concerned about the new system you propose?
To answer your question about 'lockout procedures', most 4160V switchgear has provision to open a disconnect switch and install a padlock to prevent it from being closed again. This is used for maintenance to protect the electricians from accidental turn on of the equipment. The procedure is for the maintenance personnel to install the lock and not remove it until they are done with the work. The lock has only one key so nobody else can turn on the power except the maintenance worker.
RE: Transformer remote control
RE: Transformer remote control
Alan
RE: Transformer remote control
(Note: You dont really turn on a transformer you open or close the breaker on either or both the lv and hv side)
To avoid the saftey issue, In my opinion you should have some mechanical lock that prevents the breakers / isolators closing while the equipment is being accessed. This might be done with an lock on an isolator or switch or alternatively, some circuit breaker designs allow the breaker to be opened and then "racked out." removing it from the circuit and any risk of livening up the circuit.
The maintenance works should have a visual break in the circuit that they can confirm onsite is locked from closing onto the circuit they are working on.
Hope this helps, Please elaborate on the situation if i have misinterpreted in some way.
Thanks,
Andrew
RE: Transformer remote control
The PLC control circuit should not be relied upon for the safety isolation, and neither should the local control circuit. A positive break in the power circuit, locked open by a padlock or Castell or Kirk key, or by removal of a section of conductor, and a circuit earth through an earthing switch or portable earthing device is required by most safe systems of work.
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