Breaker Tripping Remotely

Criteria? Use of the telephone mainly, to talk to people who can help, I suppose.

You are correct. Giving sound advice to you is a useless act.

Hire somebody before you kill somebody. Circuit breakers prevent equipment damage. Damaged equipment cause electrical fires.

thank you for valued information.

Because the feed information was of similar quality, perhaps?

Why do you want to know?

dear all experts ,

please go through some my observations about breaker control remotely through interposing relay.

Remote control of circuit breakers is becoming much more prevalent as the use of monitoring and central control equipment grows. When remote control is used, interposing relays are generally required to avoid a large voltage drop in the close and trip coil circuits. Here are a few thoughts on the proper selection of interposing relays.

the factors are

1. Current ratings : Interposing relay contacts used in close and trip circuits must have the ability to make and carry the current of the close and trip coils.

2. ANSI/IEEEC37.90 requirements includes

1. Tripping output performance requirements

2.Continuous and interrupting ratings of tripping output circuit.

3. Interposing relays are connected to the same control voltage supply as is used for the circuit breaker.

4. Interposing relay contacts must provide a signal duration of at least 50 ms.

5. The interposing relay coil should have a very low operating current.

6. The minimum pickup voltage for the interposing relay must be compatible with the minimum control voltage specified in ANSI/IEEE standards for the switchgear.

If you have and understand all of this information, what, exactly, are you asking? -- JHF

There are six steps:

1. Talk to the people who originally designed the equipment in the first place with a copy of every as-built drawing to hand so as to firm-up on the requirements for the modification. Make sure that both parties fully understand the scope of the work.
2. Receive a quotation for the work to be carried out.
3. Place a purchase order.
4. Arrange a shutdown that coincides with the availability of the vendor's personnel to carry out the work.
5. Test on completion of the work with a set of modified drawings to hand.
6. Pay the invoice when it comes in.

"Nothing great was ever achieved without enthusiasm." -- Ralph Waldo Emerson

Have your electrician get it from the supplier.

That's what any good manager would do.

You ARE a manager, aren't you?

It is good practice for organisations(government departments,corporations, companies etc)to employ a Consultant,who will be on line 24hrs and will visit site when required, for each kinds of jobs instead of contacting technicians from outside.

First the inhouse technician should be contacted,if he can't do speak to the consultant,who will tell your technician what to do.

The basic fallacy : the GT hv breaker is ALWAYS tipped directly by the generator/transformer protection. Interposing relay in the transformer panel will not be acceptable except in very special situations. better request the panel supplier or project consulant to set right..

dear jans,

Actually this interposing relay is not for transformer panel. its a separate unit that placed along with RTU for remote control of trip circuit only.which should operated only in critical situations.

Rahul

Dear rahul, If it is critical tripping then direct tripping is the option. If sigmal to rtu and if rtu is ruggrd direct wiring will be adequate. If rtu has to trip again it will call for a trip scheme. Better take appropriate scheme from the consultant or The panel supplier. it is not possible to suggest a scheme based on info given /p]

Interposing relay shall be immune to the induced AC voltages along its run, if the cable runs outside the building especially.

Typically, Alstom make type VAWA relays have this feature.

If the relay is expected to trip the CB then it should preferably be high burden type so as to prevent any spurious trip due to spurious AC or DC currents (induced or capacitive).