TDCR series, LUL Approved, 6 way, MCB / RCD Protected

Blakley Electrics TDCR series Transformer Distribution Cubicle combining a step-down, double-wound transformer with a double-pole RCD and MCB distribution arrangement. The product is approved for installation on LUL premises, including defined Section 12 locations, and utilises a double-wound transformer with dual 55V secondary windings to LUL specification. The assembly provides a 110 volt Reduced Low Voltage Supply (RLV) to BS 7671.

The TDCR is intended for installations with a high earth fault loop impedance (Zs), where compliance with disconnection times on 110V circuits cannot be achieved with overcurrent protection devices alone. To comply fully with LUL requirements, the TDCR is intended to supply our LV9R range of RCD protected socket outlets, as detailed in APR 1935.

Enclosure
The enclosure is of robust construction, floor standing, non-vented to IP 55 and incorporates floor fixing and wall securing brackets. The enclosure is segregated with separate compartments for the transformer and MCB sections. The transformer section is tool access only via tamper proof screws. The MCB section is accessed via a side hinged, gasketted door with quick release fasteners. Cable entry and exit is via a top mounted, removable gland plate. The enclosure is finished in an LUL approved, electrostatically applied, polyester powder paint, shade Jet Black.

Incoming Isolator
Fitted with a Schneider Electric 125A DP Isolator.

Rating
Rated at 6 kVA for 3 hours and 4.5 kVA for 8 hours. The transformer is manufactured in accordance with BS EN 61558 Parts 1 and 4 and is fabricated from materials with a Class F insulation rating.

Primary Volts
240 volts with off-load tappings at 220 and 260 volts.

Secondary Volts
The transformer will provide a line to line output of 110 volts and a line to earth voltage of 55 volts, and is in accordance with LUL drawing 2-9569-L20163 Rev 5. The transformer has dual 55 volt output windings with two earth connections. The transformer will be supplied with the main earth bond connected from B2 to earth reference A1. The connection from B1 to an independent earth is to be made by the installer at the time of installation.

Distribution
Fitted with 1 no. 63 amp, double-pole, MCB feeding 2 no. 63A 300mA selective (time delayed) 110V Type A RCDs each feeding 3 no. Schneider Electric 32A DP type ‘C’ MCBs (6 no. MCBs in total).

A wiring diagram is provided with each transformer.