AERCO KC1000 Boiler July 2011 - Manual (Page 38)

INITIAL START-UP
4-6
6. Remove all of the manometers and barbed
fittings and reinstall the pipe plugs using a
suitable thread compound.
7. Remove the combustion analyzer probe
from the vent hole. Seal the probe hole and
replace the vent connection cover.
8. Replace the unit’s panels and hood.
4.6 OVER-TEMPERATURE LIMIT
SWITCH ADJUSTMENTS
There are two Over-Temperature limit switches
that turn off the unit when the outlet water
temperature becomes too hot. The lower over-
temperature limit switch is adjustable and should
be adjusted 20 0 to 40 o F above the operating
header temperature. The upper over-
temperature limit switch is a manual reset device
and is not adjustable. It will shut off the unit if the
water temperature reaches 240°F. DO NOT
attempt to adjust its setpoint.
To adjust the lower over-temperature switch limit
switc
h:
1. Remove the wing nut from the top center of
the shell cap. Lift the cap off the shell.
2. The two over-temperature limit switches are
located at the top of the shell (see Fig. 4.6).
Do not attempt to adjust the upper switch. It
has been factory preset.
3. Adjust the lower switch between 20°F to
40°F higher than the maximum header
temperature the unit may see.
4. Replace the shell cap and wing nut.
OVER-TEMPERATURE
SWITCHES
SHELL SENSOR
209
TEMPERATURE SWITCH DETAILS
137
HARNESS
136
FROM SHELL
NC
NC
C NO
C
LIQUID LEVEL SWITCH
OVER TEMP. SWITCH
Figure 4.6
Over Temperature Limit Switch Location