These are the test benches incorporating control & measurement circuitry necessary for testing single phase as well as three phase transformers of several VA to MVA rating & voltage class of 11KV/433V,as well 33KV/11 KV, after manufacturing, repairing, reconditioning. Following tests can be done by these Test Sets. - No load Test from L.T. side
Input voltage to L.T. side. No load current. No load or excitation loss.
- Load Test
Impedance voltage. Rated L.T. & H.T. current. Conductor loss
- Temperature rise Test
Injection only at equivalent short circuit current (Temperature/Time measurement scheme is available at extra cost).
- Polarity
- Phase sequence
- Ratio error
Input: 415 volts, 3 phase 4 wire, 50Hz, AC. Range of equipment: Type | Input
| Output | Range of transformers under test | LDNLD1P1 | 230V, 50Hz. , single phase AC. | 0-240V AC at 50A 0-480V AC at 25A 0-960V AC at 12.5A | Distribution transformers from 3KVA to 250KVA i.e. 20KV primary & 480V secondary. | LDNLD3P1 | 415V, 3phase, 4 wire, 50Hz. AC. | 0 to 500V, 3 phase continuously variable AC. Capacity: 28A. | Distribution & Power transformers upto 500KVA. | LDNLD3P2 | 400V, 3 phase, 4 wire, 50Hz. AC. | 3 phase output: 0-2.75KV AC 0-5.5KV AC 0-11KV AC Capacity: 200KVA. 1phase output: 0-500V AC; Capacity: 2.5KVA. | 3 phase transformers- Upto 33KV (Ph-Ph) primary voltage & Upto 11KV secondary voltage. Capacity: 3MVA Max. 1 phase transformers- Upto 11KV primary voltage & 250V secondary voltage. Capacity: 50KVA Max. |
Protection:
- Foot switch interlock.
- Zero start interlock.
- Over load and short circuit.
- A remote interlock connector to interlock the test cage area.
Metering: High accuracy precision Digital measurement instrumentation (voltmeter, ammeter & wattmeter) scheme with metering accuracy of + 1% is incorporated. Suitable transducers are used for range transformations. Auxiliary step up transformer: Usually, these sets are made for 11KV/433-voltage class. However, additional step up transformers are available at extra cost to suit the test sets for 33KV/11KV class.
Apart from the existing Types, sets as per requirement of customer may also be manufactured. |