CHECKING CONTROLS
As the water warms up, the low stage should
cut in at approximately 49F, which is the inlet and
outlet temperature with the unit off and the high
stage should operate at 54F return.
On a four stage thermostat, the dial setting in-
dicates the cut out point of the low stage switch
which represents the average leaving water tem-
perature desired. The high stage or #4 switch
should be actuated at approximately 51F return
water temperature, #3 at 49F, #2 at 47F, and #1
at 45F, which is the dial setting. The cut in point
will be approximately 2F higher than the cut out
on each switch.
The four stage thermostat has a fixed switch
differential and fixed differential between switches.
Do NOT make any adjustments other than the dial
as this is a preset precision control.
TO CHANGE THE SET POINT:
1.
2.
3.
Loosen the setscrews on the collar below the
hex nut (see Fig. 7).
Turn the hex nut with a wrench to the point
where the desired set point is aligned with the
indicator mark.
Note
:
The set point of this controller is the
break point of switch No. 1.
Lock the setting by tightening the setscrews
loosened in step 1.
CAUTION: Response time on thermostat is slow,
approximately 5 minutes must be allowed (or bulb
response ( a f t e r a t t a i n i n g s y s t e m steady-state
operation) before any or each adjustment to ther-
mostat is made; consequently, it is practicalIy
impossible to accurately calibrate in the field).
FIGURE 7
THERMOSTATS
TWO STAGE
F O U R S T A G E
THERMOSTAT
BULB
SET POINT DIAL
SET POINT
HEX NUT
DIAL LOCKING
SETSCREW
LOCKING SETSCREW (CALIBRATION ONLY)
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