Mode Lighting’s Tiger dimming system has been around for over 20 years and is a real workhorse of the leisure retail industry.

These dimmers have evolved over the years most noticeable in the last couple of years with a face lift on the scene plates using a similar format to the evolution system single gang plates.

With these systems in exsistance in so many premises though out the UK and across the world I thought it might be helpful to point out a couple of maintenance issues that can crop up on these units over the years.

Indicator Lights:

The tiger panels have a number of useful indicator lights which give a good starting point to fault finding.

• Phase presence indicator lights : Three green or orange indicators letting you know that you have incoming phases present. (NB: prior to any internal fuses)
• Channel indicator lamps : The red indicator lamps on the dimmer cards are indicative of the control output of the relevant channel.

Electronics Fuses:

For any maintenance engineer these should be the first place to start. The power supply board on a Tiger panel has three 20mm  500mA fuses (one per phase) located next to the phase presence indicator lights. These electronics fuses provide the low voltage control supply to the dimmer cards. The supply is spread across the three phases equally and so the tell tale sign for a blown electronic fuse is the non-operation of a number of circuits on the same or adjacent dimmer cards.

DMX Inputs:

The DMX inputs on tiger systems are really useful for taking control of a system from a DMX lighting desk however in a number of installations they remain unused. These inputs take over control of the lighting channels from the scene plates when a dmx signal is detected on the input. As standard at commissioning time  it is best practice to short out the DMX data in to avoid noise problems. The tell tale of this fault is when the plates give no operation over all channels in the complete system.

Triac Faults:

This fault should be familiar to all those who maintain lighting control systems when a triac fails it usually fails short circuit meaning that the output of the dimmer always receives 240v non-dimmed and hence the faulty circuit remains on at 100% regardless of the control logic.  Triacs for tiger dimmers can be replaced easily using non-solder connections.

Warning:

Only competent persons should attempting to carry out maintenance on lighting control panels .

Lighting control panels have 240v and often 440V supply present and you should ensure and  isolate supply to panels before removing panel covers.

• Category: Technical Articles