Secondary Voltage Varies
Transformer secondary voltage can be too high, too low or there may be no voltage. Please note that transformer voltage is a ratio of the primary voltage. If the primary voltage is too high or too low, the secondary voltage will also be too high or too low.
| Check: | Solution: |
|---|---|
| Incoming line voltage varies. | A transformer is a voltage ratio device so the secondary voltage will generally vary as the primary voltage varies. This is a systems issue a transformer can not fix. |
| Verify all connection points (lugs and pads) are tight, smooth and cleaned of any insulation. | Smooth or replace pads and lugs if damaged or rough. Tighten any loose mechanical connections. Clean off any insulation remaining on electrical connection points. |
| Verify the neutral connection is properly wired and grounded per the applicable codes. All three coils should be attached to a common neutral point. | If the transformer neutral is damaged, it will have to repaired. Wire and ground the neutral per applicable codes. A coil may have been inverted during manufacturing and would have to be replaced. |
| Are there any large loads that occur where total standard or momentary inrush load exceeds the kVA rating of the transformer. | During high current, such as when a large motor is started across the line or during a short circuit, the output voltage will be lowered. The total load will either have to be decreased, limited by devices such as reduced motor starting devices or a larger transformer will have to be installed. |