CGC HKV020, Installation Operation & Maintenance

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Hybrid Vertical Stack – Installation Operation Maintenance Manual
OPERATION ‐ DETAILED
R090303 Installation Operation Maintenance Manual is subject to change without notice Page 10
The unit circuit board incorporates six relay outputs with the following uses:
•
K1 – Auxiliary relay for cooling valve on a two ‐ valve unit or heat valve on a dehumidification
unit.
•
K2 – Heating Relay
•
K3 – Alarm Relay
•
K4 – Compressor Relay
•
K5 – Low Fan or Fan Relay for belt drive units
•
K6 – High Fan or Compressor #2 on belt drive units
Each of these relays have in parallel, a green LED indicator that lights up when the relay is
energized.
The board incorporates digital inputs that are opto ‐ coupled to a 24V AC source. These inputs have
amber LED indicators that will light up when an input is present. These inputs include:
•
High Pressure Switch
•
Low Pressure Switch
•
Heat Call (W on thermostat terminal)
•
Cool Call (Y on thermostat terminal)
•
Fan Call (G on thermostat terminal)
•
Auxiliary (A on thermostat terminal)
•
Compressor shutdown (24V AC signal thru O/O).
Providing a continuous 24V potential to O/O will terminate and prevent compressor
operation. This can be used for duty cycling, or for minimizing power consumption
during a power failure, while maintaining the heating function.
•
Unit shutdown (24V AC signal thru A/O). Providing a continuous 24V AC potential to
A/O will terminate and prevent unit operation. This can be used for a simple night
shutdown. On both arrangements a single 24V AC signal can shutdown many units. ¼
va is required per unit.
The board also has four analog inputs provided via thermistors. These inputs are as follows:
•
Ta – Discharge Air Temperature
•
Tr – Refrigerant Temperature
•
Tw – Outgoing Water (system fluid) Temperature
•
Co – Condensate Level
Ta, Tr, And Tw are 10k Ohm NTP thermistors, while Co is a 100 Ohm NPT thermistor. These Inputs
do not have LED indicators.