Safely Isolating a Single Phase on a Ritherdon CT Chamber

The Ritherdon CT chamber is an insulated enclosure made to mount the electricity meter and to house the current transformers and is a tamper-proof and sealable unit. Designed to be safe, but also quick and easy to install.

The individual covers which protect the electrician allow work to be carried out in the CT chamber on one phase without having to isolate the complete unit.

Benefits of the Ritherdon CT Chamber:

  • Lugging tool not required
  • Switch off and safely work on a single phase
  • CTs quickly and securely clips onto the terminal rail
  • Pre-Wiring is included for connection to CTs and Meter
  • Safe and easy to operate testing unit
  • Rating up to 309 KVA / 430 Amps

The requirement for CT Metering:

Metering using current transformers or CTs is required when the energy supply is typically greater than 100 A (~70 kVA at 415 V).  This is known as CT Metering or using current transformers to measure a current that is too high to measure directly or where the voltage of the circuit is too high. The current transformer is used to provide an isolated lower current in its secondary which is proportional to the current in the primary circuit. The induced secondary current is then suitable for measuring using an electricity meter.

The Ritherdon CT Chamber comes populated with:

  • A DIN rail for mounting the current transformers.
  • Three separate single phases and a neutral phase.
  • A pre-wired WAGO terminal test block.

Current Transformers or CTs are supplied separately. We supply 200 amp set of three metering class CTs and 400 amp set of three metering class CTs, including individual test certificates. The CTs supplied are moulded case current transformers and come with a DIN rail mounting clip.

The enclosure is supplied separately to the backplate so that weight is not an issue. The backplate is easily secured inside the enclosure after it has been mounted onto the cut-out and fixed to the wall.

  Ritherdon CT Chamber


Contact us for more information on the supply of the Ritherdon CT Chamber, separate CTs, or if you’d like to opt for a Supply and Fit Service in conjunction with Siemens engineers. We understand that the requirement for CT Chambers often arises when it is necessary to energise the site and we deliver to a lead time of  2-3 working days. Lead times for Supply and Fit, have a standard lead time of 10 working days.

Urgent requirement?

Head to our Shop Online and find –

Ritherdon CT Chamber

Set of 200 Amp Metering Class CTs

Set of 400 Amp Metering Class CTs


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