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.

4 rooms with standalone I/O DSI modules were commissioned plus a larger system consisting of 45 ballasts, a mixture of zumtobell and philips,

Commissioning was carried out using the browser interface to the Edin NPU which allows full configuration and provides DALI commissioning tools.

“All were all identified very quickly with no problems, the Dali commissioning interface works very well”. D Aberdeen – Lighting Control

Installation of the New Mode Lighting Edin Din rail products.

This recent small works solution designed as a simple bolt-on to an existing LEAX Panel and an centralised emergency lighting system fed from an inverter.

The Edin panel takes over the DSI control of four channels of emergency lighting in the event of a power failure ensuring that the lighting is ramped up to an emergency level.

Working on a recent project I came across these interesting transformers.

They allow connection of lov voltage lighting at greatly increased distance from the transformer while maintaining an optimum voltage.

The system uses a sensing cable which provides a feedback loop (similar in concept to those used in analogue sound processing) to monitor the lamp voltage and voltage drop in the cable and hence compensates for any variation and stabalises the lamp voltage.

The box itself houses a large transformer at the top with an electronic controller below. The units provide luxury service to the halogen lamps giving improved brightness, better colour rendering, longer lamp life and lovely smooth dimming.

The units can be controlled by 1-10v and 0-10v control as standard with DSI and DALI versions available.

These transformers hark back to the old days of centralised transformers but without all the cooper! They offer an alternative to leading edge dimming systems and provide a great solution.

More details:

Multiload

Be sure to check out the MLC2500 Lamp conserver product from the same manufacturer.

Microphonics

As those of you who know me will be aware I am a big fan of Automation. The use of sensors in control systems is the clever and progressive way forward.

Putting light switches when they are not the best solution is a waste of money, time and energy. However specifiers and installers are still scared of occupancy sensors.

They are scared of the call-out when Mr Client has been plunged into darkness while reading his paper in “The Library”.

This has been a real problem and often the only way to counter the problem is to up the time delay off to a sufficient level that we are confident that a traditional good quality PIR occupancy will re-trigger the time delay off.

This of course is not an ideal solution as we end up having lights and fans on burning energy for longer than we should have.

Some companies looked at gate sensors systems by which a control system could monitor a person entering and leaving a space and combine these with a PIR to get a more accurate result. These systems have a number of limitations including the problems cause by multiple users and high cost due to the requirement for multiple sensors.

Sensor Switch have produced a dual technology sensor which combines a PIR detector with a high gain microphone and some clever audio processing to achieve a good result.

Motion is first detected by  the PIR and the the microphone is switched on to listen for continued occupancy.

The system filters out repetitive noises such as plumbing and HVAC sounds to allow the sensor just to trigger from sudden noise changes such as created by a user.

I will be very interested to find out how well the unit deals with background music!

Lot of articles on the internet cover the electronic details of what DMX is which is of interest to those wishing to create products that send or receive and wish to comply to the standard. This is of no interest to lighting designers and electrical contractors. The architecture of a DMX control system is governed by the other side of the standard EIA485 this describes the electrical system that DMX uses as it’s bedrock. This is the roadway that the communication runs on; if this underlying infrastructure is not correct then the communications trying to use it will falter and the system will never be stable and reliable.

DMX Standard was originally adopted for use by “lampys” at touring events where large entertainment systems are setup up for a show or a series of shows before being all packed up into a number of trucks and moved to the next show.

Power distribution for these shows is all done using flexible rubber cable and Ceeform cables connecting different parts of the systems using portable distribution units. The construction industry has a more cost effective and longer lasting method using steel wire armour and fixed distribution boards around a project.

The distribution for a project is designed in a drawing office by an electrical engineer.

Power Distribution Drawing

The engineer designs the system by  completing calculations and specifying suitable cabling and distribution panels to ensure that the system will work correctly and safely.

DMX is used by the construction industry primarily to control colour change lighting. By it’s nature a single colour change unit uses three or four channels of DMX and puts a unit load on the DMX controller of the system.

In the same way as the electrical distribution example above DMX requires design. It’s a simple thing to say but frequently the architecture of a DMX system is left to chance. When a ring main is required in a electrical system often the exact numbers of outlets and types of outlets will not be specified or indeed if a small change is required then the installing electrician will make the design change in a flash. This is simple as a the architecture (limits on length, number of outlets, spurs) is well known by that electrician through years of installing these simple systems.

DMX is a simple architecture however colour change systems can use a large number of DMX recievers and control channels. In addition to this systems should be designed to allow section testing by isolation and also to ensure downtime in certain areas of the system will not affect control over other parts of the system.

Simple DMX systems have a single cable connecting a number of fittings allowing a controller to control attributes on all these fittings independently. In reality all but the most basic DMX systems require boosters, splitters and termination to allow a stable system to exist and to ensure minimum installation time.

DMX is a not a proprietary control standard it is used by countless manufacturers and the size and complexity of DMX control required in a project is on the increase all the time.

So don’t chance it ! Were here to help!

Energy saving light bulbs have taken over the world in the last couple of years so much so that later this year (2009) the major retailers in the UK plan to remove filament light bulbs from there shelves.

However in most projects with lighting controls low energy light bulbs are not to be found. In fact most systems do not support them.

Dimmable energy saving light bulbs are still in the early days of development and are not yet as cost effective as their non-dimmable predecessors.

Lighting control systems can however give significant energy savings.

• Control empowers correct usage of multiple fittings. With more circuits to control only the lighting that you need for a task need be turned on saving 100% on lighting that is not required.
• Off during non-activity: Using timed off’s and proximity sensors in a lighting control system we can ensures that lights are not left on when the need not be.
• Daylight harvesting: Daylight harvesting allows lights to be automatically dimmed to a level dependant on the amount of natural light reaching the target area. This saves in energy usage as the quantity of additional lighting used is limited to what is required exactly.
• Dimming at full power: Not running lamps at 100% can result in massive extension of lamp life.

Contact us to discuss how you can implement energy saving in your next project.

Mode Lighting units such as the tiger and Evolution have no main isolator and hence even in the previous edition of the regulations a mechanical isolator was required to isolate the incoming power to the unit to carry out mechanical and electronic maintenance.

A recent project meant i had to explain a RS232 integration to non technical users.

RS232 is a very simple way of communicating between two systems.

You can think of it as a simple speech communication a good example being the exchanges of speech that go on in a parliment or any sort of debate.

Members of parliment wish to speak to the house but if they all speak together then the message will be lost or confused due to the inability to hear the different messages coming from each parlimentarian.

To solve this problem RS232 has hardware flow control or handshaking.

When each member of the house has a message they stand and raise there hand to say that they are ready to speak. The speaker of the house then indicates to one member that the house is ready to hear their message and in this way one message at a time is heard.

I an RS232 system only one line of commuication is established. Imagine a secretary and her boss dicatating a letter but the secretary has no short hand skills. Each small section of the letter dicatated by the boss is brought to an eand by the Secretarty saying “STOP” while she finishes writing that section on the word processor. When the secretary is ready to continue she indicates this to the boss and the next section .

In the RS232 system these “STOP” and “GO” messages are indicated by the high or low level of the CTS flag. The sending system has a similar flag (RTS) which indicates that it has data ready to send to the recipient.

	9 Pin Connector on a DTE device (PC connection)
Male RS232 DB9
Pin Number	Direction of signal:
1	Carrier Detect (CD) (from DCE) Incoming signal from a modem
2	Received Data (RD) Incoming Data from a DCE
3	Transmitted Data (TD) Outgoing Data to a DCE
4	Data Terminal Ready (DTR) Outgoing handshaking signal
5	Signal Ground Common reference voltage
6	Data Set Ready (DSR) Incoming handshaking signal
7	Request To Send (RTS) Outgoing flow control signal
8	Clear To Send (CTS) Incoming flow control signal
9	Ring Indicator (RI) (from DCE) Incoming signal from a modem

But as anyone who sets a daily alarm knows automation is not great when the alarm wakes you up on a Saturday morning instead of allowing you your well deserved lie in!

This is a very simple example of how automation requires a really well thought out quality specification. When setting the alarm the simple choice is to tick the “every day of the week” !

When doing lighting controls a basic automation requirement is that lights turn off automatically after all staff have left the premisis. This ensures that if lights are left on they will not stay on all night which saves on lamps and energy costs.

However on special occasions for example the christmas party the premisis is to be used after closing to host the party or on a special corporate launch night you invite your major client to a reception to lanuch your latest new product.

The presentation is then cut abruptly short as the lights dim to zero. At best this causes inconvinience and at worst can present a real health and safety problem as people are literaly left in the dark.

I remember an example of this would happen each year at our local church. The exterior of the building is floodlit by the local council controlled from a timer control located in a panel outside the church. Each Christmas the midnight service to bring in Christmas day would take place at 10:30pm and church-goers would be able to find there way around the church from the light of the floodlights. However on Christmas morning the lights would turn off at 12:30 am meaning that we would exit the church to darkness!

The simple solution has been provided in HVAC systems for many years. A three position switch on a panel allow selection of “OFF” , “ON” and “AUTO”. This allows the system to be forced off , forced on and forced to do whatever it is supposed to do depending on any automation that has been programmed into the system.

This is a really simple local overide that works and should be used as a starting point for local overide.

However our automatic specification was written to stop somebody leaving the lights on overnight. This local overide gives them exaclty this power again so we have failed to meet the specification.

Another heating control analogy is the “+1h” button or “Next Step” button often found on simple heating controllers this enables the users to slightly atler the auto mation by telling the system that for the next hour it is one hour ahead of the real time (allowing you to turn on or off the heating early) or to tell the system that for the rest iof this period of automation you want the system to do the functionality of the next period of automation.

This is better as the period of non-automation is restricted if you like the automation is automatically switched back on!

There are many methods of solving this problem and unfortunately often the problem is solved by removing the automation due to the fear of an un suspected turn off.

With good design features of lighting controls systems can be fully utilised and not hindered.