Martindale NC4 Dual Sensitivity Non-contact Voltage Tester
Martindale NC4 Dual Sensitivity Non-contact Voltage Tester – Voltage Pen Detector, Dual Voltage Volt Stick w. Torch, Circuit Tester & Martindale CP501 Classic Check Plug 240V Socket Teste
Martindale CP501 Classic Check Plug 240V Socket Tester
Sold in over 2 million units, 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 bright 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 fail-safe system means that any LED not lit indicates a fault. The robust ABS housing has a sculpted shape for easy removal and there is a look up chart on the tester for quick fault diagnosis.
The plug induces less than 5mA of earth leakage, well below RCD trip thresholds.
- Quick & easy testing of socket wiring with the UK’s favourite check plug
- Detects 28 fault conditions
- Three bright LEDs with clear & simple fault codes on the plug
- Tough sculpted design for easy removal
- CAT II 300V – Built for safety
| Colour: | Red |
| Pack Quantity: | 1 |
| Quantity: | 1 |
Unlike some similar products, this one has excellent sensitivity. It is much safer to have too much sensitivity, rather than too little.
A case would have been useful, I just have to be careful over where I place it in my toolbox. It looks a little delicate.
I wanted to have a non-contact tester that would indicate lower voltages such as 110V. Having recently bought the Martindale VT12 Voltage Tester and found it to be very good (see my review) I took a punt on the Martindale NC4 as a companion device.
The NC4 has two sensitivity ranges 12-1000V AC (not DC) and 50-1000V AC with a nice audible alert and flashing red LED when it detects my 240V domestic supply (I don’t have anything lower in AC to test). It also has a handy LED torch function.
When you first switch on the NC4 the bright red LED flashes once a second to indicate that it is in the 50-1000V range. Briefly pressing the button again switches to the 12-1000V range and the red LED flashes twice in one second. Turn off the NC4 by pressing the green button for 2 seconds or it will eventfully auto-power off.
I did a 240V test of how well it works where there are three wires in close proximity. I cut the end off a cable exposing the Live/Neutral/Earth to a length as you would when fitting a UK plug. I then plugged the other end into 240V so making one of the three exposed wires live with the other two dead cables close to the Live.
In the 50-1000V range the NC4 probe had to be approximately within 3mm of Live for it to alert, it did not alert when placed near the other cables even though they are close to the Live. In tight spaces it is unlikely that you will get false positives from cables that are not live when they are close to a Live. That is an excellent result, I’ve read reviews where these devices are far too sensitive and pick up so-called “live” cables when in fact they are picking up the Live from one close-by. I much prefer to be almost touching the Live cable, the probe is long and suited for this very purpose.
In the 12-1000V range you merely have to be within 50mm of the cable for it to detect Live, handy for checking thicker cables and wall/light sockets (it isn’t sensitive enough to detect cables within walls). You’d also use this when waving it around to find a Live cable and then you’d switch to 50-1000V to focus in onto the individual Live cable.
As with any device there is the odd gotcha with these things that can trip you up:
When using a non-contact tester it is important to know that when testing cables you should move the probe all around the circumference and up and down the length of the cable as the Earth cable could be blocking the detection of the Live in a twisted core. You should of course test the device on a known Live before use (and after use if it didn’t find anything as it could be faulty!).
As with any device of this nature (like neon screwdrivers) you should NEVER use it to test for dead. These devices are not reliable enough to put your life at risk, in a tight space these devices can easily be fooled if the Earth wire is blocking the Live wire. Use with caution and know the limitations of your kit.
If you must rely on a device for testing for dead then a Martindale VT12 is absolutely what you should be using. I can not stress the importance of using a VT12 to test for dead and not one of these non-contact devices, or you might be dead yourself!