With over 2,000,000 of these socket testers sold, the Martindale CP501 is the most popular socket tester available. The classic check plug is a quick and easy way to ensure that 13A sockets are correctly wired, indicated by 3 high brightness, long life LEDs.

Wiring faults are indicated by one or more of the LEDs failing to illuminate, with the pattern of lit LEDs indicating the type of fault detected. This is a fail-safe system that means that any LED not lit indicates a fault.

The improved housing design of this socket tester is virtually indestructible, housed in a flame retardant ABS case. The plug induces less than 5mA of earth leakage, well below RCD trip thresholds.

The classic check plug can be purchased individually, or as a pack of 10.

Note: Like all other standard socket testers, the Martindale CP501 will not detect common earth and neutral or earth neutral reversal.

Mains Supply

200 - 250V (30-70Hz)

Power Consumption

<1.2W

Temperature Range

-10°C to 40°C, 60% RH (max)

Earth Leakage

<5mA

Overvoltage

CAT II, 300V

Housing

Flame retardant ABS

Dimensions

65 x 65 x 47mm

Martindale CP501 Specification Sheet

Martindale Check Plug Instruction Manual

Will socket testers spot all mains wiring faults?
No, they cannot tell if the earth and neutral wires are reversed and most conventional testers can only tell if the earth is disconnected.

Please click the links below to download the application notes in pdf format.

Socket testing safety