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Frequently asked questions

Answers to the questions customers ask us most, from choosing and fitting a dimmer to curing flicker. Search, or browse by product or topic.

Showing 12 questions about V-Pro Micro Show all questions

Choosing a dimmer

Which dimmer suits your lights, how much lighting it can take, and dimming from more than one switch.

Which dimmer do I need for my LED bulbs?

For dimmable LED lighting choose a V-Pro dimmer: our flagship range, designed for modern LED lighting, with push on/off switching and rotary dimming. The V-Pro family also includes:

  • V-Pro Multiway: a dimming knob at 2 or 3 switch positions;
  • V-Pro Smart: control from your phone, Alexa or Google Home;
  • V-Pro Multi-Point: tactile touch at any number of switch positions, with infrared remote control at the master;
  • V-Pro Micro: hidden behind retractive (push) switches.

If your LED lights or driver need leading-edge (triac) control, or you have more than 300W of LED on one dimmer, choose V-Com.

Always choose lamps that are described as dimmable. Not sure? Answer a few questions in our dimmer chooser.

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How many lamps can my dimmer control?

Add up the wattage of all the lamps the dimmer controls: the number of lamps times the watts printed on each. The total must not be more than the maximum load per gang on the dimmer's label and data sheet. For example, 8 LED downlights of 5W each add up to 40W.

DimmerLoad per dimmer (gang)
V-Pro0-120W or 0-300W, no minimum load
V-Pro Multiway, V-Pro Smart120W, no minimum load
V-Pro Multi-Point100W (1 to 10 dimmable LED lamps), no minimum load
V-Pro Micro160W of dimmable LED
V-Com0-100W, 15-180W, 15-220W, 20-400W or 40-600W (the first figure is the minimum)
V-Dim (halogen)Up to 1000W, depending on model; at least 100W recommended: see the V-Dim guide

PowerGrid grid dimmers also have a maximum per plate: single plate (1 to 2 gang) 400W, twin (3 to 4 gang) 800W, double twin (6 to 8 gang) 1200W, triple twin (9 to 12 gang) 1800W, and no more than 800W per row.

With low voltage lighting, add up the VA ratings of the transformers, not the wattage of the bulbs: see transformers and dimmer load. For lamp-by-lamp advice see our compatibility guides.

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Can I dim the same lights from more than one switch?

Yes. Choose by how you want to dim:

  • A dimming knob at every switch (2 or 3 positions): one V-Pro Multiway dimmer with one or two companion controllers. 2-way and 3-way kits are available (MJKIT2W, MJKIT3W).
  • Phone or voice, plus knobs at up to 3 positions: one V-Pro Smart dimmer with one or two V-Pro Multiway companion controllers.
  • Touch at any number of positions: one V-Pro Multi-Point master dimmer with as many supplementary controllers as you need, up to 50m of cable. Infrared remote control works at the master only.
  • Push (retractive) switches at any number of positions: a V-Pro Micro in-line dimmer pack.

Ordinary switches can't be used as the other positions with these systems: V-Pro Multiway and V-Pro Smart need companion controllers, and V-Pro Multi-Point needs Multi-Point supplementary controllers. If dimming from one switch is enough, a V-Pro dimmer works with an ordinary 2-way switch.

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How do I work out the dimmer load when there are transformers in the circuit?

Add up the VA ratings of the transformers, not the wattage of the bulbs. Choose transformers with a rating close to their lamp load, e.g. a 50VA, 60VA or 70VA transformer for a 50W low voltage bulb.

  • VARILIGHT transformers: any number, as long as you keep within the maximum rating of the dimmer. For YT40DC12 and YT40DC24 LED drivers, never more than 250W per dimmer circuit.
  • Other brands: use only fully dimmable electronic transformers, and no more than 5 per dimmer circuit.
  • V-Plus dimmers (recommended for halogen on VARILIGHT transformers): load to 75% of the dimmer's maximum.
  • Transformer specifies triac dimming: use a V-Com dimmer.

Wire-wound or toroidal transformers are not suitable for V-Pro, V-Pro Multiway, V-Pro Multi-Point, V-Pro Smart or V-Dim dimmers. If your transformer does not say that it is dimmable it is unlikely to work with any dimmer.

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How does the V-Pro Micro in-line dimmer work?

The V-Pro Micro (MDJ160) is a small in-line dimmer that hides behind a light switch or ceiling rose. It is controlled by retractive (momentary) switches, the type that spring back after they are pressed: a short press turns the lights on or off, a long press dims them up or down. It dims up to 160W of dimmable LED and remembers your last brightness.

For more switch positions, wire more retractive switches in parallel: only one Micro pack is needed per lighting circuit, and every switch can dim. It does not need a neutral at the switch. For separate up and down buttons, choose the MDJ160K with a centre-off retractive switch. Driving mode, minimum and maximum brightness, Boost, child lock and reset are all set from the switch: see set up your dimmer.

See the plain English guide and the MDJ160 and MDJ160K instructions (PDFs).

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Setting up and programming

Dimming modes, minimum and maximum brightness, resets, and pairing supplementary controllers, remotes and the app.

V-Pro and V-Com rotary dimmers

I've changed the bulbs on my dimmer: do I need to do anything?

Yes. Always turn off the mains power before replacing bulbs controlled by a dimmer. If you have changed the type of bulb, reset the dimmer to its factory settings: V-Pro and V-Com, V-Pro Multiway, V-Pro Multi-Point, V-Pro Smart, or any range in set up your dimmer.

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Some LEDs won't come on at low brightness: what is Drive (Boost)?

Drive gives LEDs that won't switch on at low brightness a short boost at start-up. On V-Pro and V-Com dimmers:

  1. Set the knob to minimum.
  2. Switch the lights on and off once per second.
  3. Set the knob to maximum, and switch on and off again.
  4. Set the knob to minimum and switch the lights on.
  5. In configuration mode, turn the knob up until the lamps switch on.
  6. Leave it for 5 seconds to save.

To turn Drive off, repeat the steps but skip step 5. The same feature is called Boost on V-Pro Multiway, in the V-Pro Smart app and on the V-Pro Micro, where it is set from the switch: see set up your dimmer.

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Fitting and wiring

Wiring 2-way and multi-way circuits, wall box depths and where to find the instructions. If in doubt, consult a qualified electrician.

Dimmers

Do I need a neutral wire?
  • V-Pro Smart and V-Pro Multiway dimmers: no. They install in place of a standard switch, and neutral must never be connected to the dimmer itself.
  • V-Pro and V-Com rotary dimmers: no. They connect to the switch wires only (terminals C, L1 and L2).
  • V-Pro Multiway companion controllers: they can be wired with or without a neutral (see the companion controller instructions, PDF).
  • V-Pro Micro: no neutral is needed at the switch. Follow the leaflet: it warns not to connect the neutral to the main dimmer unit.

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Where can I find the instructions or a wiring diagram for my product?

The instruction leaflet, with its wiring diagrams, comes with your product. You can also find every current leaflet on the instruction leaflets page, and leaflets for older and discontinued products on the earlier leaflets page. Where relevant, check the software version and choose the correct leaflet: the software version is on the side of the dimmer module.

We also have a page of wiring diagrams and how-to videos. Every data sheet links to the product's leaflet: type the product code into the search box. If the wiring diagram is not enough, please contact a qualified electrician.

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What do I need to remove before an insulation test?

Dimmers from all of our ranges should be disconnected for the duration of the insulation resistance test. Failing to do so could damage the dimmer and make the product guarantee invalid.

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Troubleshooting

Dimmers that have stopped working, flicker, buzz or glow, and other problems with installed products.

Not working, or switching off

My dimmer has stopped working: what should I do?

Many faults can be cleared without replacing anything. Switch off at the mains before touching any wiring and, if in doubt, consult a qualified electrician.

  1. Reset the power. Switch the lighting circuit off at the circuit breaker, then back on after a few seconds. An overloaded dimmer switches itself off to protect itself, and touch and remote dimmers can often be reset this way.
  2. Check the load. Add up the wattage of all the lamps on the dimmer (for low voltage lighting, the VA ratings of the transformers). It must not be more than the maximum per gang on the dimmer's label. See how many lamps a dimmer can take.
  3. Changed the bulbs? If you have changed the type of lamp, reset the dimmer to its factory settings: V-Pro and V-Com, V-Pro Multiway, V-Pro Multi-Point, V-Pro Smart, or V-Pro Micro in set up your dimmer.
  4. New installation? Check the wiring against the diagram in the instruction leaflet. A touch or remote dimmer must have a true live connected to its "Live" terminal: it must not be switching neutral.
  5. Lights come on but won't dim? See my dimmer won't dim the lights.

If it still doesn't work, the dimmer may be faulty. It is covered by our lifetime guarantee: see how to make a claim. It helps to have the product code, the batch number (printed on the plastic moulding at the back of the dimmer) and the type and wattage of your lamps to hand.

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Flickering, buzzing and glowing

My lights won't dim low enough, or go off at the lowest setting
  • Too bright at the lowest setting: reduce the dimmer's minimum brightness.
  • Off or flickering at the lowest setting: raise the minimum brightness. If some LEDs won't switch on at low brightness, turn on Drive (Boost), which gives them a short boost at start-up.

When the dimmer is installed, all the lamps must stay visibly on at the lowest brightness setting (UK EcoDesign Regulation 1194/2012). How low a lamp will dim varies according to the brand and type of LED: see our compatibility guide.

The same settings on other dimmers: V-Pro Multiway, V-Pro Multi-Point, V-Pro Smart (in the app). V-Pro Micro is set from the switch: see set up your dimmer.

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Still stuck?

Our customer services team will help. To get the quickest answer, tell us the product code, the batch number from the back of the dimmer, and the make, wattage and number of lamps.