Marmonix MRCD-1 Socket Tester – RCD Test, NCV & Voltage Display

The Marmonix MRCD-1 socket tester plugs into a mains socket and shows on its screen whether the wiring is correct, the live-to-neutral and earth-to-neutral voltage, and whether the RCD trips on its >30 mA test. It also has a built-in non-contact voltage (NCV) detector for checking cables and switches before you touch them. It is a quick first-pass check for electricians, facility teams and homeowners in the UAE and GCC. See the other Marmonix electrical testers, or use a voltage detector for single-pole checks.

MRCD-1 socket tester: what it checks

• Wiring status: L, N and E indicators plus a reversed-polarity symbol show correct or faulty wiring at a glance
• Voltage display: L-N and E-N voltage, 0.1–250 V at 40 Hz–1 kHz, with a high-voltage indicator
• RCD trip test: >30 mA test current at 220 V ±20 V; press for under 3 s
• NCV detection: active at power-on, with a faster beep and power bar as the field gets stronger
• Low-battery indicator, running on 2 × AAA batteries
• 3-pin Type G plug (the UK-style socket used in the UAE), compact 65 × 65 × 60 mm body, CE marked

Wiring conditions shown by the MRCD-1

MRCD-1 specifications

How to use the MRCD-1

1. Plug the tester into the socket. Read the L, N and E indicators and the L-N and E-N voltage on the screen.
2. If the wiring is correct, and only after switching off connected equipment and getting permission, press the RCD button for under 3 seconds. A working RCD trips.
3. Reset the RCD. Then use NCV mode to screen nearby cables, switches and outlets before deeper fault-finding.

Clean the tester with a damp cloth only. For load and energy checks on plug-in appliances, see the Marmonix MMP-10 micro power monitor. For circuit measurements, use a digital multimeter.

What’s in the box

• MRCD-1 socket tester
• 2 × AAA batteries
• User manual
• Certificate of conformity
• Warranty card

Case study: socket and RCD checks after a nuisance trip

When an RCD trips, the next job is to prove the socket wiring and confirm the residual-current protection still works, before you reset it and leave. With the MRCD-1 the electrician plugs in, reads the wiring status and voltages, runs the RCD trip test, and then uses NCV to screen neighbouring outlets, all with one plug-in tool. Open earth, reversed polarity or a missing neutral show up on the first pass without a separate meter.

Further reading: Electrical test and measurement instruments: the complete guide

MRCD-1 socket tester: common questions

Does the Marmonix MRCD-1 test RCDs?

Yes. With the tester plugged into a powered socket, press the RCD button for less than 3 seconds; a working RCD rated at 30 mA trips. The RCD test works at 220 V ±20 V. Switch off connected equipment and get permission before testing, because the test cuts power to the circuit.

Which wiring faults does the MRCD-1 show?

The screen shows correct wiring, missing neutral, missing earth, live and earth reversed, live and neutral reversed, live and earth wrong with earth missing, missing live, and live-only conditions, using the L, N and E indicators.

Does the MRCD-1 show the socket voltage?

Yes. It shows the live-to-neutral (L-N) and earth-to-neutral (E-N) voltage across a 0.1–250 V range at 40 Hz–1 kHz, with a high-voltage warning.

Can the MRCD-1 find live wires without plugging in?

Yes. NCV (non-contact voltage) mode is on as soon as you power the tester. Hold it near a cable or switch; the beeper speeds up and the bar indicator rises as the field gets stronger.

What power does the MRCD-1 use and what comes in the box?

It runs on 2 × 1.5 V AAA batteries, and a low-battery symbol tells you when to change them. The box has the tester, 2 AAA batteries, user manual, certificate of conformity and warranty card. Marmonix gives a 2-year warranty.

Is a socket tester a replacement for a full installation test?

No. A plug-in tester is a quick first check of wiring, voltage and RCD trip. Earth resistance and insulation resistance need dedicated instruments such as an earth resistance tester or an insulation tester.