[SML] Source 4 Power and LED Cabling

[David Fox]

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100VAC to 240VAC 50/60 Hz universal power input
 Neutrik power in and thru connections
 Requires power from a non-dim source
 Up to nine fixtures (15A max) may be linked via power thru
connector (ten fixtures total per circuit) when used with R20
Relay Module or Unison Echo Relay Panel. Consult breaker
trip curves when used with other equipment
? Inrush
-- 120V: 11A (First half-cycle)
-- 240V: 15A (First half-cycle)

Why can't they just say: Max current draw x.xAmps?
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Alf asks a good question that I would like to answer. The short answer is because Inrush is different than max draw. 

Lemme explain:
Unlike a traditional incandescent source, when you first power any driver or ballasted fixture ( like an  LED) there is a spike in power consumption that exceeds normal operating power consumption. This can be significantly higher than normal use. In some fixtures the first few cycles is significantly more than normal operating voltage. Think a factor of 6-10 times higher. 

This means that if a fixture normally consumes let's say 5 amps, when you first turn it on it may consume up to 50 amps for those first few cycles. Some fixtures even run this high inrush for several seconds. 

So if you have a dimmer or relay rated for 20 amps, and you connect 4 of them, your initial draw is 200 Amps. Crazy right? 

We discovered this with Source Four HID and Irideon fixtures years ago and started building extra protection into our modules, relays and breaker design to sustain inrush for the first few cycles without nuisance tripping. This is called a trip curve. 

So the information from the cut sheet above, while seeming less than clear based on how incandescent fixtures consume power, is accurate for how LEDs consume power. 

Using our relays, you can connect up to 9 ColorSource fixtures to a single relay and avoid nuisance tripping. Nine fixtures together draws 15 amps normally (Approx. 1.6 amps each), but inrush in each fixture is 11-15 amps for the first half cycle depending on voltage ( 99-135 amps). 

Thus our caution  that if you are not using ETC power control, it is important to know the trip curves of your breakers. This is specifically to avoid following the cut sheet and still experiencing nuisance tripping. 

I hope this makes some sense and helps. This is a tricky and new issue. 



Wayne;
I am happy to help you find someone in your area who can work with you on the best solutions for your system. Contact me off list.



David Fox 
Training and Documentation Specialist
ETC
Direct 608-824-5056  
Direct Toll Free 888-908-2193 

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