60
•
Heater pumps P1a, P1b, P1c and P1d operate during the relevant heaters CFH and are delayed
'OFF' (according to Post Purge parameter in BOILER menu) after the burner has shut down.
•
If system pump P2a is controlled by the heaters, P2a operates whenever the enable/disable switch
(if fitted) is closed or a switch bridging wire (default) is present between field wiring terminal strip
'Enable/Disable' terminals 11 & 12. Note: If indirect DHW priority is activated (Indirect Priority
Enable parameter = ON), system pump P2a will turn off whenever an indirect DHW CFH is present
for the programmed time period (Priority Ovr Timer parameter). Indirect DHW priority is optional
for operation mode 2, however system pump P2a must be controlled by the Master to enable
indirect DHW priority.
•
Indirect DHW pump P3a operates during an indirect DHW tank CFH and turns off after indirect
DHW CFH is satisfied (with no delay 'OFF').
•
Optional outdoor air compensation: Optional outdoor air sensor S4 can be utilised to automatically
adjust the target water temperature as the outdoor air temperature changes. For outdoor air
compensation to operate, Target Mode parameter must be set to RSET. The CFH for heat target
is then calculated and determined according to Boiler Start and Boiler Design parameters and the
outdoor air temperature detected by outdoor air sensor S4.
Operational Settings
•
Operation Mode parameter in ADJUST menu must be set to 2 (refer to
on page 60 for parameter settings and
on page 88). Note: Indirect DHW priority
is selectable for operation mode 2 and can be configured to override for an adjustable time period.
•
A bridging wire (or optional aquastat) must be installed between field wiring terminal strip 'Indirect
DHW Override' terminals 10 & 12 to permit indirect DHW operation.
•
Set auto reset high limit switch to 90ºC (194ºF) on each heater.
•
The PIM operator setpoint dial
MUST
be set to the Indirect DHW
Setpoint temperature on each heater to prevent a DHW over
temperature condition from occurring when operating in limp mode.
•
Heater A VERSA control board DIP switch 2 must be set to ON
(Master). Heaters B, C and D VERSA control board DIP switch 2 must be set to OFF (slave). Refer
to Cascade System Connections on page 77.
Mode 2
– ADJUST Menu Settings for Hydronic System with Indirect DHW
•
'Default' column shows factory default settings. Actual values will depend on installation. Required
(Rqd) values shown bracketed in bold must be used or not exceeded where ‘Max’ is shown.
•
Parameters can only be changed if VERSA control board DIP switch 1 is set to ON (up).
•
Some parameters are only available if controlling parameter/device is set as indicated in
‘Description’.
Parameter
Range
Description
Default
(Rqd)
Operation
Mode
1, 2, 3
Selects heater operating mode
1
(2)
Target
Mode
SETP, RSET,
EMS, Modbus
SETP = Setpoint
RSET = Outdoor Reset (outdoor air compensation)
EMS = Energy Management System (if PIM DIP switch 5 is
ON - Default DIP 5 setting is OFF)
Modbus only if Modbus Mode para = Temp or Rate)
SETP
Target
Setpoint
10.0 ~ 115.0°C
Target setpoint (only avail if Target Mode para = SETP)
82.0°C
(80ºC Max)
Target
Max
32 .0~ 110.0°C
Max heating value for indirect DHW @ 10.0vdc input when
Target Mode para = EMS or Modbus
98.0°C
(82.0ºC Max)
Target Min
10.0 ~ 82.0°C
Min heating value for indirect DHW @ 1.0vdc input when
Target Mode para = EMS or Modbus
10.0°C
Manual
Diff
(1)
1.0 ~ 23.0°C
Only available to be viewed/changed if PIM DIP switch 1 is
ON.
PIM DIP switch 1 should be set to OFF.
5.0°C
