Camus Hydronics DRW1000, Installation And Service Manual

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When a boiler is set as Lead Lag Master = Enabled and Modbus
address = 1, the controller of this boiler will drive the lead lag
operation.
The outdoor temperature sensor connected to the slave boiler 2
(ie. B-2) will be the outdoor sensor for the lead lag system
•
The system temperature sensor connected to boiler 1
(the master) in terminals labeled “Outdr/Sys” in the
junction box will be the control sensor for lead lag
operation.
•
The start/stop signal connected to boiler 1 (the master)
at terminals labeled “Remote Operator” will be the heat
demand input for lead lag operation.
When demand for heat is present the lead boiler will start and
uses the lead lag parameters for boiler modulation. After a
period of “Interstage delay” the master boiler compares the lead
lag temperature with the lead lag set point and will check if:
1) An additional boiler is needed
Lead lag temp < Lead lag setpoint – Add stage Error
threshold
2) Number of boilers remain the same
Lead lag > Lead lag setpoint – Add stage Error
threshold AND
Lead lag temp < Lead lag se Drop stage Error
threshold
3) A boiler should stop
Lead lag temp > Lead lag se Drop stage Error
threshold
4) All boilers off
Lead lag temp > Lead lag se off hysteresis
If the lead lag master system is interrupted the remaining
boilers will operate as standalone boilers based on the Central
Heat or DHW parameters when set to “Enabled”.
Rotation
Rotation time is configurable based on equalized run time
(default) or a fixed rotation schedule.
Interstage Delay
The length of time to wait between starting the next boiler in
sequence. (Default: 2 minutes)
Base Load Rate
When a call for heat is initiated the lead boiler runs up to the
desired base load rate (Default: 80%) and continues to operate
in this fashion based on the above 4 scenarios. If the lead lag
temperature is not satisfied a second boiler is fired and they
would both operate up to 80% fire rate.
Slave State
Slave Status Manager
Unknown Table entry is unused or empty
Available Slave is operational and ready to use
Add Stage Stage is getting ready to fire
Suspend Stage Stage was getting ready but is not needed
Disabled Slave is locked out or disabled
Recovering
Slave is in time delay to verify that it is
operational before considered to be available
Wiring the Lead Lag Setup
Use Cascade terminals in the junction box to wire lead lag
appliances
Master Slave 2 .. Slave 7
J3, MB2
A A .. A
B B .. B
C C .. C
Figure 28: Lead Lag Wiring Setup (Left: Master, Right: Slave)
NOTE
Recycle power on all boilers after programming is complete if
lag boilers are not discovered automatically
NOTE
CH Setpoint or DHW Setpoint must match Setpoint located in
Lead Lag Master Configuration in order for the system to
operate correctly.
NOTE
The Local/Remote switch (explained below) must be set in the
“Local” position on ALL lag boilers.
6.4 LOCAL/REMOTE SWITCH
The local remote switch mounted inside the control box is
designed to deliver an enable signal either relying on an external
contact closure (Remote) or enabling the boiler locally (local).
When Remote is selected via the SPDT switch the Remote
Operator contacts in the junction box must be closed to deliver
an enable signal. When Local is selected via the SPDT switch a
constant enable signal is present. When troubleshooting the
Dynaforce® it is recommended to switch to Local mode.
6.5 COMM. PORT 2 ACTIVATION
> > > Select Gateway tab