AERCO Esteem O&M Manual - Manual (Page 61)

55
Adjusting Outdoor Reset Curve
C
AUTION
!
If a parameter setting is changed but the
STORE button is not pressed to save
the setting, the MCBA will automatically
store the setting after 20 minutes. En-
sure all parameters are at their factory
settings or appropriately revised for the
application prior to commissioning the
boiler. Failure to comply could result in
erratic or unreliable operation of the Es-
teem 399 Low NOx boiler.
N
OTICE
Once a parameter setting has been
revised and stored pressing the STEP
button will display the setting of the
next parameter without showing P_XX.
To avoid confusion, continue pressing
the STEP button until Parameter 46 is
reached. The next press of the STEP
button will cause the display to roll over
to Parameter 1. Continue pressing the
STEP button until the next parameter to
be adjusted is reached and revise the
setting.
Adjusting Outdoor Reset Curve
Parameters 4, 10, 11, & 12 define the settings
of the outdoor reset curve. See Graph 1 and
Table 3, page 57 for an example of modifying
the outdoor reset curve.
CH M AXIMUM B OILER O PERATING S ETPOINT
(Parameter 4)
If an outdoor temperature sensor is not con-
nected to the boiler, the setpoint for a heating
call will be the space heating Maximum Boiler
Operating Setpoint. If an outdoor tempera-
ture sensor is connected, the CH Maximum
Boiler Operating Setpoint becomes the boiler
setpoint on the CH Reset Curve Coldest Day.
The outdoor temperature can be monitored on
the boiler display via item 4 of the INFO menu.
CH M
INIMUM
B
OILER
O
PERATING
S
ETPOINT
(Parameter 10)
When an outdoor temperature sensor is con-
nected, the CH Minimum Boiler Operating
Setpoint becomes the boiler setpoint on the
CH Reset Curve Warmest Day.
CH R
ESET
C
URVE
C
OLDEST
D
AY
(Parameter 11)
This parameter is not applicable if an outdoor
sensor is not connected to the boiler. When an
outdoor temperature sensor is connected, the
CH Reset Curve Coldest Day is the coldest
design temperature of the heating system.
CH R
ESET
C
URVE
W
ARMEST
D
AY
(Parameter 12)
This parameter is not applicable if an outdoor
sensor is not connected to the boiler. When an
outdoor temperature sensor is connected, the
CH Reset Curve Warmest Day is the warmest
design temperature of the heating system.
Factory Setting Minimum Setting Maximum Setting
186ºF 86ºF 194ºF
Factory Setting Minimum Setting Maximum Setting
00ºF (-)22ºF 50ºF
Factory Setting Minimum Setting Maximum Setting
86ºF 60ºF 140ºF
Factory Setting Minimum Setting Maximum Setting
64ºF 60ºF 78ºF
GF-125