Lochinvar Harmony Installation And Operation Manual page 6

INPUTS
A1 T
TEMP
A2
A3
SHUTDOWN
A4
A5 +
A6 S
A7
NETWORK
A8
A9
SYSTEM
PROVE
A10
WARNING: The SYSTEM PROVE
input can not be used as a safety
limit. All equipment must have its
own certified limit and safety con-
trols as required by local codes.
BOILER
ACTVE
INPUTS
B1
STAGE
A
B2
B3
STAGE
B
B4
B5
STAGE
C
B6
B7
STAGE
D
B8
WARNING: The BOILER ACTIVE IN-
PUTS can not be used as a safety
limits. All equipment must have its
own certified limit and safety con-
trols as required by local codes.
6
• The System Prove feature is provided to check system component
operation.
• A typical use of this feature is to check for flow before firing any
boiler stages. When there is a call for heat, the System Output
activates the system pump starter. When the pump establishes flow,
a flow switch closes together the SYSTEM PROVE input. Only then
can the Harmony activate boilers and modulate them as required to
hold the temperature set point.
• If the SYSTEM PROVE input is open on a call, the Harmony will
enable only the System Output. All Stage outputs will be off when
the SYSTEM PROVE input is open.
• A factory installed jumper provides the System Prove signal. Do not
Dry Contact
remove the jumper unless it will be replaced by a System Prove
System Prove
signal.
Signal
• The System Prove signal must be a dry contact only. No voltage can
be placed across the SYSTEM PROVE - A9, A10 terminals.
• Bring the two wires from the dry contact to the terminals marked
SYSTEM PROVE - A9, A10.
IMPORTANT: Do not remove the factory installed System Prove
jumper unless it is replaced by a System Prove signal. If the
SYSTEM PROVE input is not closed, the Harmony will NOT
activate stages.
WIRING THE BOILER ACTIVE INPUTS
• A closure across the BOILER ACTIVE terminals informs the Har-
mony that a boiler is running normally. If the BOILER ACTIVE
terminals open, the Harmony registers that the Stage has encoun-
tered a safety limit and can not be restarted without a manual reset.
The Harmony will not reactivate or modulate a Stage which is not
Active.
Dry Contact
• The Boiler Active signal is not a safety, but use of these inputs will
Active Signal
significantly improve the Harmony's set point control performance in
the event of a Stage encountering a safety limit.
• A pair of BOILER ACTIVE terminals is provided for each stage.
• The Boiler Active signal must be a dry contact closure from the
boiler controlled by that Stage's output. For example, the Boiler
Active signal wired into terminals STAGE A (Terminals B1 and B2)
must come from the unit whose operating limits are connected to
terminals OPERATING LIMIT OUTPUTS A (Terminals 5 and 6).
• The BOILER ACTIVE terminals are dry contacts only. No voltage
can be placed across the them.
• Wire the Boiler Active signals to their respective STAGE terminals:
- STAGE A to Boiler Active Input terminals B1&B2
- STAGE B to Boiler Active Input terminals B3&B4
- STAGE C to Boiler Active Input terminals B5&B6
- STAGE D to Boiler Active Input terminals B7&B8