Installation
Voltage Transformer Installation
Installing the voltage transformers that give a recloser its control supply and its measurement reference.
A recloser needs voltage sensing to do its job. The voltage transformer provides both the measurement reference the protection uses and, in many installations, the auxiliary supply that keeps the control cabinet running.
We install VTOP series transformers for 11kV, 22kV and 33kV networks, mounted and connected as part of the wider recloser installation rather than as a separate visit.
What VT installation covers
- Mounting and mechanical fixing of the transformer
- Primary connection to the network
- Secondary wiring into the recloser control cabinet
- Earthing of the transformer and secondary circuit
- Polarity and ratio verification
- Confirming the secondary supply is correct before energising the control
What matters in practice
-
Polarity is checked, not assumed
A VT connected with reversed polarity produces measurements that look plausible and protection decisions that are wrong. It gets verified during commissioning.
-
Secondary earthing
The secondary circuit needs a single, deliberate earth point. Multiple earths or none at all both cause problems that are hard to diagnose later.
-
Auxiliary supply reliability
Where the VT feeds the control supply, its reliability determines whether the recloser stays operational. The backup battery covers up to 48 hours, not indefinitely.
-
Matched to the network
Ratio, burden and voltage factor are specified for the application. A transformer that is electrically adequate but wrongly specified for burden will not perform to its accuracy class.
Related services
Need VTs installed?
Tell us what you need and where the site is, and we will scope the work and quote it.