Master Phase Loss Detection (MPLD) Interface and Phase Loss Detection Interface Troubleshooting

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The information in this post is provided to assist in troubleshooting. Perform work at your own risk. ENSURE ANY POWER FROM DEVICES HAS BEEN DISCONNECTED BEFORE SERVICING ANY EQUIPMENT. If you do not feel comfortable performing the work, please contact us or your local service center. Be aware that ETC and its Affiliates are not responsible for any damage or injury caused by service of our products by anyone other than us or our authorized service providers, and such damage is excluded from the product’s warranty.

Issue

The system is in Emergency Mode and will not switch back to Normal Mode.

Explanation

The Master Phase Loss Detection (MPLD) Interface and Phase Loss Detection (PLD) Interfaces are designed to send an emergency signal to your ETC lighting system. This can be triggered by several different situations, including a fire alarm, remote panic switches, or loss of Normal Power. To troubleshoot the MPLD or PLD Interfaces, please follow the steps below.

WARNING: The steps below require the Interfaces to be powered on. This work should be carried out by a licensed electrician wearing proper PPE safety gear.

Solution

For MPLD:

Check power and continuity:
1. Check for all 3 phases normal power feeding into RL1.
2. Check continuity between positions/pins 1 and 8 on RL1. If AC voltage is good on all phases but no continuity, the relay is bad and should be replaced.
3. If voltage is missing on any phase, de-energize and check continuity on the fuses upstream on the terminal block.
4. In the case of Phase A missing, also check local Test Switch for continuity. If there is good AC andgood continuity on the RL1 + Test Switch, move to next step.
1. 24 volts DC (VDC) should be present on RL2-RL7 between positions 7 and 2. If 24VDC is present, check continuity between positions 1 and 3 on RL2-RL7 as well as positions 8 and 6 on RL2 and RL3. If relays have 24VDC but no continuity, bad relay and it should be replaced. If no relays have 24VDC, check the DC Power Supply.
2. If RL4-RL7 do not have 24VDC, check the TS2 terminal, or Fire Alarm through Spare Out/Return pairs. Each pair should either have connected wires or jumpers. If connected wires, continuity should be present across pairs. If RL2 and RL3 do not have 24VDC, go to next step.
Check continuity across TS6-1 and TS6-2, or "Series PLDs Out and Return". It should have connected wires or jumper. If no continuity, check series PLDs (see note below). If continuity is good, go to next step.
Check continuity across TS5-1 and TS5-2, or Remote Panic Switch. It should have connected wires or jumper. If connected wire and no continuity, bad remote panic switch, or switch is in panic state. If good continuity, go to next step.
Check Local Reset switch. Should have continuity across positions 13 and 14 only while switch is depressed. If no continuity when pressed, switch is bad.

For Series PLDs:

Check power and continuity
1. Check for all 3 phases normal power feeding into RL1.
2. Check continuity between positions/pins 1 and 8 on RL1. If AC voltage is good on all phases but no continuity, the relay is bad and should be replaced.
If voltage is missing on any phase, de-energize and check continuity on the fuses upstream on the terminal block.
A temporary workaround in case of bad PLD: Jumper TS2-1 and TS2-2, or IN and THRU.

Please contact your ETC dealer or ETC Technical Services for Part numbers.