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© 2010 D 265 - 07/10
SETBACK (OCC and UNOCC)
To provide greater energy savings, the control has a setback feature. With setback, the
supply water temperature in the system is reduced when the building is unoccupied. By
reducing the supply water temperature, the air temperature in the space may be reduced
even when thermostat(s) are not turned down. Any time the
UnO Sw
(5) and the
Com
(1)
terminals are shorted together, the control operates in the unoccupied mode. When in the
unoccupied mode, the
UNOCC
segment is displayed in the LCD. The control adjusts the
supply water temperature based on the
UNOCC
settings in the control.
COMBUSTION AIR OR ALERT CONTACT
The control has an isolated contact that can be used as either a combustion air damper contact or an alert contact. This selection
is made using the C.A. / Alert DIP switch.
Combustion Air (C.A.)
When the DIP switch is set to C.A., terminals 15 and 16 can be used as a switch to operate a combustion air damper. This contact
closes prior to the first boiler operating on the control. The amount of time that the contact closes prior to the first boiler firing is
set using the combustion delay setting.
The combustion air contact remains closed for a minimum of 15 seconds after the last boiler is turned off.
Alert
When the DIP switch is set to Alert, terminals 15 and 16 can be used as a switch to operate an alert circuit. This contact closes
whenever an error message is present on the control display. When the alert contact is activated, refer to the Error Messages
section of this brochure to determine the cause of the alert. Once the fault has been fixed, pressing either the
Menu
,
Item
,
▲
or
▼
button will clear the alert.
Boiler Alert
The control can monitor the boiler supply temperature and provide an alert if the temperature does not increase within a certain
amount of time. The amount of time can be set using the Boiler Alert setting. This alert can be used to determine if the boilers
have failed to fire. To reset the alert, press and hold the
▲
and
▼
buttons for 5 seconds while in the VIEW menu.
ROTATION
The control includes an Equal Run Time feature which changes the firing
order of the boilers whenever one boiler accumulates 48 hours more
running time than any other boiler. After each rotation, the boiler with the
least running hours is the first to fire and the boiler with the most running
hours is the last to fire. This function ensures that all of the boilers that
are being rotated receive equal amounts of use. When the
Rotate
/
Off
DIP switch is set to the
Off
position, the firing sequence always begins
with lowest boiler to the highest boiler.
Fixed Lead Rotation
In some applications, it may be desirable to have the first boiler fire first
at all times while the firing sequence of the remaining boilers is changed
using Equal Run Time Rotation. This rotation option is selected by
setting the
Fixed Lead
/
Off
DIP switch to the
Fixed Lead
position.
First On / Last Off or First On / First Off
When using the
Fixed Lead
rotation option, a selection must be made between
First On
/
Last
Off
and
First On
/
First
Off
using the DIP switch. When
First
On
/
Last
Off
is selected, the lead boiler is always modulated first and shut off last. When
First
On
/
First
Off
is selected, the lead boiler is always modulated first and shut off first. This DIP switch is only read by the control
when the
Fixed
Lead
/
Off
DIP switch is set to
Fixed Lead
.
Resetting the Rotation Sequence
To reset the rotation sequence, set the
Rotate
/
Off
DIP switch to the
Off
setting for 5 seconds and then return the DIP switch to
the
Rotate
setting.
RUNNING TIMES
The control displays the accumulated running time of each boiler in the VIEW menu.
Resetting the Running Times
To reset the running time for each boiler, select the appropriate running time in the VIEW menu. Next press the
▲
and
▼
buttons
simultaneously until
CLr
is displayed.
1
2 3 4
5
Com
–
Boil
Sup
Boil
Ret
Out
+
UnO
Sw
Timer Switch
1
2
720 hours
672 hours
2
1
672 hours
720 hours
