Watts AERCO AM Series Quick Installation Manual page 5

Quick Installation Guide
AM Series
Electrical/Controls Wiring - BOILER

Install a 15 am fused disconnect or service switch. (15 amp). All electrical conduit and hardware should be installed so that it does not interfere with
the removal of any cover, inhibit service or maintenance, or prevent access between the unit and walls or another unit.

All AM Series pump relays are rated for 3A max. When pumps used exceed 3A, an appropriately sized external relay or starter must be used.
CONNECTING UNITS IN CASCADE:
Up to eight boilers or water heaters may be combined in a cascading
system using the optional Cascade Sequencer. Refer to the AERCO
Cascade Sequencer user manual (GF-146-CS) for installation details.
MODBUS INTERFACE CONNECTIONS:
The AM unit can be controlled from a building management system via MODBUS
interface. This requires a Communication Module on each unit (AM399-1000: factory
installed; AM199/250: optional). Refer to the AM Series MODBUS User Manual (GF-
146-MB) for wiring and setup details.
QIG-0001_0A • 11/1/2019 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
To program the settings indicated below, see Page
6 for control panel button functions.
BOILER APPLICATION Basic Wiring and Settings:
•
Main Power supply: Terminals 101/102/PE
•
Low Water Cut Off: Terminals 103/104
•
Primary Pump (boiler loop): Terminals
113/114
•
Constant Setpoint Enable/Disable (if
employed; otherwise jumped): Terminals
10/11
Set Para. 2003=0
•
Outdoor Sensor (if employed): Terminals
14/15
Set Para. 2003=1 (Outdoor Reset)
See O&M for additional settings for Outdoor Reset
•
0-10VDC (if employed): Terminals 22/23
Set Para. 2003=4 (0-10V)
Notes on 0-10VDC analog input:
- analog input drives the supply
temperature
- requires a Communication Module on
each unit (AM399-1000: factory
installed; AM199/250: optional).
- See O&M for additional settings when
controlling via 0-10VDC.
•
Indirect Fired heater sensor (if employed) *:
Terminals 12/13
Set Para. 3012=1
See O&M for additional settings for Indirect
Fired Water Heating
•
Indirect Fired heater pump: Terminals
107/108
•
Secondary Pump (system loop): Terminals
105/106
STARTUP PRECEDURE - BOILER APPLICATION
(Prior to startup, see page 7 for Combustion Calibration)
1. Open the manual gas shutoff valve.
2. Turn power switch ON
3. Change heating setpoint: C/A. Press B to save.
4. If an indirect water heater is connected use R/S to change
domestic hot water temperature. Press B to save.
NOTE: If the burner fails to ignite within 60 seconds, the
boiler will attempt ignition another four times. Consult O&M
manual if the boiler reaches a lockout condition after four
ignition retries.
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