Over the years, we have manufactured enclosures for all the major distribution network operators (DNOs) in the UK. These include the CT Chamber and other metering panels for UK Power Networks, MOD units for Electricity Northwest, HV COP 3 and LV COP 5s for Scottish Power and Western Power Distribution.
We manufacture metering panels from metal and plastic and have a well-established supply chain for whichever components are preferred by our customers. The focus at Ritherdon is on the higher end of quality and safety in our industrial metering panel designs.
With the introduction of the Building Network Operator, organisations responsible for multi-occupancy buildings (e.g. landlords) now have more options for how they manage their networks and also what metering equipment they use.
Our “BNO CT Chamber” has a long track record in the south and south east of England (UKPN network) and is described as the “Rolls Royce” of CT Chambers due to its build quality and safety features. It is also relatively small and versatile making it much easier to install. Find out more about how we developed the CT Chamber together with UKPN.
What is a Building Network Operator?
A Building Network Operator (BNO) is an “organisation (often the owner or landlord) who operates the electricity distribution network within a multiple occupancy building between the intake and the customers’ installations”. The BNO is responsible for the design and installation of the electricity supply network within their building.
The responsibility of the Distribution Network Operator (DNO) now ends just above the “cut out” or “intake position”. As long as the Wiring Regs (BS 7671), other guidance (e.g. BS 9999 for fire safety) are adhered to and the P283 commissioning test is carried out, the choice of what equipment is installed in the building and who installs it is up to the BNO. This includes the CT Chambers.
The ‘BNO CT Chamber’
In a BNO-managed building, the responsibility of the DNO now ends just on the usage side of the cut-out (intake position) and, as long as the Wiring Regulations are followed, the choice of electrical equipment beyond this point is the BNO’s.
What is a CT Chamber?
A CT Chamber is a chamber that houses current transformers or CTs for low voltage metering applications. It is also known as a metering panel. CT Chambers are required to transform high voltage to low voltage for metering purposes on for multi-occupancy residential or commercial property.
When the supply to a site needs to be greater than 100 Amp (~70 kVA at 415 V) then the electricity meter works with current transformers (CTs) housed within their own enclosure – the CT chamber. The power cables come onto the site, via a cut-out unit, into the CT Chamber and the Meter Operator (MOP) typically mounts their meter on the CT chamber.
The Ritherdon CT Chamber include CTs (Current Transformers) and are available in 200 Amp, 400 Amp and 600 Amp versions. Current transformers are Class 0.5s.
What are CTs?
CTs or current transformers are devices used to measure high currents safely. It steps down the current passing through it and produces a proportional current for measurement or protection purposes in electrical circuits.
Current transformers are vital components in electrical systems, designed to measure and monitor electrical currents. They play a crucial role in protecting equipment, ensuring safety, and enabling efficient energy management.
Our Moulded Case Current Transformers are designed with a protective housing, which provides insulation and safeguards against external environmental factors. They are compact and provide excellent mechanical protection.
We offer 600/5, 400/5 and 200/5 in class 0.5s. The 0.5s class measures more accurately between 1% and 100% of the rated power.
CTs are included in our CT Chamber in 200 Amp, 400 Amp and 600Amp and available to purchase separately too.
Reasons to use the Ritherdon CT Chamber:
- Proven track record as the ‘top of the range’ unit for installation, quality and safety features in the southeast of England.
- Built-in flexibility, so they can be installed in a variety of positions to accommodate incoming supply from the bottom.
- The front panel can be hinged from either side to accommodate local space and access requirements.
- Avoids the requirement for costly lugging of tails. Our CT panels are designed to accept sector stranded, sector solid or rounded stranded conductors.
- Accepted by all meter operators.
- The meter operator can house their meter on the front panel. This avoids requirement for further meter panels and the complexity of running multicore wiring to adjacent locations.









