ELV Modules and Test Mode in Sensor CEM, CEM3, DRd
This information is accurate as of 7/29/11.
Going back to the first release of Sensor/Unison ELV modules, there has been a lot of discussion about their function with a rack in test mode. After some investigation, here are the facts as we currently know them:
CEM+/CEM3
The ELV module circuit must be powered (with the breaker on) before getting a control signal in order for the module to output.
Why?
The processor in the ELV module needs to see a zero on the pwm line before it is ready to output. With CEM+/3, test mode supplies a constant +5V signal starting before the module boots so the ELV never starts outputting.
Ramification
In a Sensor+/3 rack in test mode, it is possible for a working ELV module to have signal LEDs illuminated with no fault indication and still not output.
- Breaker trip/reset on a previously working circuit in test mode
- Rack running in test mode
- ELV module signal LEDs on and output circuit on.
- Turn module breaker off
- Signal LEDs stay on, output circuit off.
- Turn module breaker back on
- Signal LEDs stay on, output circuit stays off.
- Rack running in test mode
Note: This will only occur in test mode. In normal or set levels operation, the pwm signal will be turned off for zero cross blanking time during every half-cycle and the ELV will output after its breaker is reset.
- Rack power applied with test mode active (a.k.a. How an EC may turn on lights during installation)
- Power on rack with CEM+/3 installed in test mode
- ELV signal LEDs on, output circuit off.
- Loosen the CEM+/3 from the backplane and reseat.
- ELV signal LEDS on, output circuit on.
- Power on rack with CEM+/3 installed in test mode
Caution: Do not remove the CEM+/3 from the rack. To maintain arc flash protection, keep the module within the rack -- only unseat/reseat it from/into the backplane.
DRd
DRd uses zero cross blanking time even in test mode. Consequently, an ELV should turn on even after a breaker trip/reset. However, there is a software bug that may inhibit test mode function in some versions of DRd code.
- In DRd dimming engine versions 1.0.2 and below and 1.2.0 and above, a slot configured for an ELV module will turn on in test mode.
- Affected
- PACP 2.0.1+; 1.0.0-1.1.2 (but not 1.1.2b)
- SACP 1.2.0+; 1.0.0-1.0.1
- Affected
- In DRd dimming engine versions after 1.0.2
- A slot configured for an ELV will not turn on in test mode.
- An ELV module in a slot inaccurately configured as a standard (Dxx) dimmer module will turn on in test mode.
- Affected
- PACP 1.1.2b-1.2.2
- SACP 1.1.0-1.1.4
In Brief: The ELV will fire with CEM+/CEM3 test mode IF these steps are followed:
- Insert the dimmer into the rack and turn on the dimmer circuit breakers.
- Put the CEM+/3 into test mode.
- Insert the CEM+/3 in the rack and/or energize the rack.
Basically, if you provide power to the ELV10 before the CEM+/3, the ELV10 will not fire.