AERCO Control System (ACS) - Manual (Page 39)

MC2: 04/23/13 Page 39 of 144
GF-131
AERCO Control System (ACS)
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288
Installation, Operation, and Maintenance Manual
OMM-0081_0D
2.16 RELAY PANEL COMPONENTS
2.16.1 Power
The power connector is located at the left side of the wiring panel. It uses single phase AC
power from 110 to 240 VAC, 60 Hertz.
2.16.2 Inputs
The inputs are all dry switch (digital) inputs. The specifics are below:
• Aquastat In (Temperature) Switch
This switch input comes from the aquastat temperature switch located in the DWH
storage tank. The switch should have at least a 3 degree hysteresis or deadband.
• Valve End Switch In 1 & 2
These switch inputs come from the end switches of Valve 1 and Valve 2, respectively.
The valve end switches should close when the valves are completely open.
• Aux Relay Contact In
This switch input comes from the dry contact “Aux Relay” output of the ACS.
• Sys Relay Contact In
This switch input comes from the dry contact “Sys Relay” output of the ACS.
2.16.3 Outputs
The relay outputs are all dry contact and can switch up to 5A at 120VAC, or ?240 VAC. The
switch outputs connect directly to the ACS and are all dry contacts. The specifics are below:
• DHW Pump Relay
This SPST relay is used to activate a DHW pump when the DHW Aquastat is calling for
heat. When the Aquastat stops calling, the relay will remain activated for ?1 minute
before turning off.
• Valve I Relay
This SPDT relay controls the valve between the Building Priority boilers and the DHW
Priority boilers. The Normally Open (N.O.) contact is connected to the Valve 1 Open
and the Normally Closed (N.C.) contact is connected to the Valve 1 Close input. For a
valve with “spring return open” or “capacitor return open”, the N.O. contact would not be
used.
• Valve 2 Relay
This SPDT relay controls the valve between the Building boilers and the Building Priority
boilers. The Normally Open (N.O.) contact is connected to the Valve 2 Close and the
Normally Closed (N.C.) contact is connected to the Valve 2 Open input. For a valve with
“spring return open” or “capacitor return open”, the N.C. contact would not be used.
Interlock 1
4 Relay – These are 4 SPST relays used to enable or disable the Building Priority boilers
in this 2-valve system.
• Aquastat Switch Out
This SPST contact connects to the “Setback” input of the ACS.
• Valve End Switch Out
This SPST contact connects to the “Interlock 1” input of the ACS.