Electra DCI 80, Service Manual

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12-3
CONTROL SYSTEM
Revision Y05-02
Service Manual - WNG 50_60_80 DCI
12.2.7 Dry Contacts
Dry contacts are used to interface the system with an external building management system
(BMS).
• Night input. Switches the system to night mode when closed.
During night mode, the outdoor unit speed will be reduced in order to reduce the system
noise level.
• SB input. System will be turned to Stand-by when the contact is closed.
• Power Shedding input. Limits the maximum power consumption when closed.
• Forced Mode input. Used to force the operation mode of the system
• Alarm output indicates a failure at the system.
Alarm output will be activated when there in the following ODU Faults/Protections
1 to 6, 8 to 22, 24, 25, 27 and 28.
Alarm output will be OFF when the Fault/Protection is cleared.
12.2.8 Temperature Sensors
CTT – Compressor Top Temperature
OAT – Outdoor Air Temperature
OMT – Outdoor Middle Temperature
OCT – Outdoor Coil (heat exchanger) Temperature
HST – Heat Sink Temperature
12.2.9 Base Heater
Heating element designed to defrost any ice that is accumulated on the outdoor unit base
during low heating operation.