Location on site

The equipment should be located taking heed of the following points:

  1. Access

At least 1000mm is required for access in front of all removable cover, but subject to local/site regulations which may dictate greater clearances. Removable access to leave metal must be located in a secure environment.

  1. Ventilation

Neutral Earthing Resistors may become very hot during operation. A free-air flow environment is required around the resistor enclosure with a recommended minimum of approximately 250mm.

  1. Safe Working

High Temperature–During normal service either due to steady state current flow (if specified), or a fault condition, both the issuing air temperature and the enclosure surface temperature may exceed 100°C.

Equipment or combustible materials must not lie on the top cover of the enclosure or be in contact with the sides.

Installation Stages

  • A flat foundation is required.
  • The Neutral Grounding Resistor is supplied assembled.
  • No special tools are required.
  • Lifting equipment must be capable of lifting the NGR weight is given on the rating plate.
  • Place the Neutral Grounding Resistor on the prepared base.
  • Remove front and back covers.
  • Drill gland plate as required.
  • Check fixing integrity of resistors.
  • Examine for signs of damage during transit (i.e., check that the both enclosure and support structure are undamaged). It means that there are no broken insulators and the resistor elements are secured on their mountings.
  • Secure the Neutral Grounding Resistor on to its base. For a concrete base, use expanding bolts or rag bolts which penetrate at least 100mm in to solid ground.
  • Ensure that all connections are tight.
  • Refit back cover.
  • Connect incoming cable.
  • Carry out commissioning checks as detailed below.
  • Connect outgoing cable (Resistor Earth).
  • Refit front cover.
  • Connect enclosure earth bonding cables as required.
  • Check all enclosure bolts are tight.

Installation, Operation and Maintenance