AERCO KC1000 Heater w/Mod-Box Controller - Manual (Page 27)

INITIAL START-UP
22
8. Replace the unit’s panels and hood.
9. Remove the combustion analyzer probe
from the vent hole. Seal the probe hole and
replace the vent connection cover.
4.6 TEMPERATURE CONTROL
CALIBRATION
Although the unit comes factory set and
calibrated for a 130
0
F setpoint it is usually
necessary to recalibrate temperature control.
There are two main adjustments for performing
temperature calibration. These are OfSt (offset),
and SENS (sensitivity).
Adjustments to OfSt and SENS are made at
minimum and maximum load conditions and
should be made in increments of 1 to 3. After
making an adjustment, outlet water temperature
must be allowed to settle for several minutes
prior to making further adjustments.
When calibrating temperature control observe
the following:
A) The unit must be in operation and in AUTO
mode.
B) Use the outlet temperature and percent input
displays to set load conditions and see the
effect of adjustments.
C) Perform the calibration in the SECONDARY
menu of the temperature controller.
D) Make small adjustments and allow time
between adjustments for the outlet
temperature to stabilize.
E) Maintain water flow as constant as possible
during these adjustments.
F) Ensure that recirculation loops are operational
while the calibration is being performed.
4.6.1 SETTING THE OUTLET WATER
TEMPERATURE SETPOINT
The setpoint of the unit may be changed by
following the procedure below. Once a setpoint
has been changed recalibration may be
necessary. The temperature calibration
procedure is outlined in step Sections 4.6.2 and
4.6.3
1. Enter the SECONDARY menu of the
temperature controller by simultaneously
pressing
!
and ENTER.
2. Press INDEX until SEtP is displayed. This is
the unit’s desired outlet temperature.
3. Adjust this value to the desired set point
using
! "
then press ENTER to accept the
value.
4.6.2 MINIMUM LOAD ADJUSTMENT
1. Place the control in the secondary menu by
simultaneously pressing
!
and ENTER.
2. Press INDEX until Pct is displayed. This is
the unit’s percentage of firing rate.
3. Create a minimum load on the system that
will yield a steady percentage of firing rate
between 25% to 35%.
NOTE:
It may be desirable to shut off the outlet
valve and use the hose bib to simulate a
minimum flow load condition.
4. Press the INDEX button until tout appears in
the lower display. The upper display will be
indicating the outlet water temperature.
5. Wait a few minutes to allow the outlet
temperature to stabilize.
NOTE:
Keep toggling between the outlet
temperature and input percentage to ensure
that both have stabilized.
6. Once stabilized the outlet temperature
should be 2 to 3 degrees above the unit’s set
point. If it does not stabilize to 2 or 3 degrees
above the setpoint, Offset (OfSt) must be
adjusted.
7. To adjust OfSt press INDEX until OfSt
appears in the lower display (see figure 4.6).
8. Raise or lower OfSt as needed using the
!
&
"
buttons. Increasing this value will
increase water temperature, decreasing it
will decrease water temperature.
9. Press ENTER to accept new values and
allow time for the system to settle between
adjustments.
FIigure 4.6
Secondary Menu Displaying Offset