AHRI K2WT, Installation, Operating And Service Instructions

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Figure 10.1: Location of High and Low Voltage Printed Circuit Boards (PCB)
The use of the pump outputs are as follows:
a) System Pump - Pumps water through the radiation. This pump is hydraulically separated from the boiler pump, either
by closely spaced tees, or by a hydraulic separator. The system pump is always on when the system is responding to a
call for CH. Depending on the DHW configuration, it may also be on during a call for DHW.
b) DHW Pump (“IWH Circulator”) - Pumps water directly through the indirect water heater.
Maximum combined current draw for all circulators is 6.3 FLA. See Section XII of this manual for information on setting
up the pump operation.
2) Low Voltage Connections – Low voltage field connections on the low voltage PCB are shown in Figure 10.3 and are listed
from top to bottom:
• Heat T’Stat - 24VAC heating thermostat (R - 24V “Hot”)
• Heat T’Stat - 24VAC heating thermostat (W - Energized or Call for Heat)
• Heat T’Stat - 24VAC heating thermostat (C - 24V Common)
• DHW Stat - 24VAC domestic hot water thermostat (1)
• DHW Stat - 24VAC domestic hot water thermostat (2)
• External Limit - Field supplied low voltage safety limit contacts (1)
• External Limit - Field supplied low voltage safety limit contacts (2)
• Alarm Contact (1)
• Alarm Contact (2)
• EnviraCOM Device (D)
• EnviraCOM Device (R)
• EnviraCOM Device (C)
X. Wiring
(continued)
HIGH
VOLTAGE
PCB
LOW
VOLTAGE
PCB
WIRING
COMPARTMENT
WIRING COMPARTMENT
COVER NOT SHOWN