Test Meter PRO TMP990 Audible Socket & RCD Tester

Test Meter PRO TMP990 Audible Socket & RCD Tester

The Test Meter PRO TMP990 Audible Socket & RCD Tester provides a quick and reliable method for testing wiring in standard 230V UK wall sockets. With a simple one-step process, it indicates wiring faults through a red/green LED display as well as an audible buzzer. The TMP990 also has a fault-type chart on the front of it displaying the order of LED faults for quick reference.

Beyond basic wiring verification, the TMP990 incorporates advanced testing functions for enhanced safety diagnostics.

Earth Volts Touchpad

The earth volts touchpad detects if the earth voltage is greater than 50v AC, helping identify potentially hazardous situations. The TMP990 must first be plugged into the socket under test: if there is a polarity fault, the LEDs will indicate the error and the touchpad test will not be allowed. However, if there are three green LEDs with a continuous buzzer tone, then the polarity is correct.

At this stage, the operator can touch the touchpad with an index finger. If there is voltage greater than 50v AC on the earth of the socket, the three green LEDs will switch to red and a pulsing buzzer will sound, signalling the need to stop testing and investigate the cause of the high earth voltage.

RCD test

The TMP990 also performs an RCD trip-time test to verify that a 30mA RCD disconnects within 300ms when a nominal 30mA earth fault current is applied. The procedure is simple. Just plug in the TMP990 into the socket under test, and if a polarity fault is detected, the LEDs will indicate the error, and an RCD test cannot proceed. However, if there are three green LEDs and a continuous buzzer, then the polarity test is correct.

If the RCD has tripped within 300ms, then power to the socket will be disconnected, resulting in all LEDs and the buzzer switching off. If the RCD didn’t trip in that time, then the first two LEDs will change to red, while the third remains green, and the buzzer pulses before the tester resets itself. After approximately 4.5 seconds, the TMP990 will return to the correct polarity mode.

In cases of a high earth resistance that could cause a potentially dangerous voltage rise above 50v as a result of the RCD test, the TMP990 will automatically abort the test. Under these circumstances the LEDs will change to three red LEDs with a buzzer pulsing for 4.5s and the unit returning to the correct polarity mode.

part number: TMP990

Key Features

• One-step testing process of 230V UK socket wiring
• Fault type indication
• Red/green LED display
• Audible fault indication
• Earth volts touchpad detects voltages >50V AC on earth
• RCD trip-time testing (30mA within 300ms)
• Automatic test abort under high earth resistance conditions