Xylem MM 235E Replacement Snap Switch Assembly SWA 150S 150S MD 158S 159S - Manual (Page 10)

PUMP
SWITCH
PUMP
SET SCREW
N
PUMP OFF
PUMP ON
BURNER
“CUT-OFF LEVEL”
AT CAST LINE
10
ADD ADHESIVE HERE O
5b. If the Pump Off point does not match the one shown in chart for the
control (pages 3 and 4) and as measured on the "Switching Level
Ruler", dig the inspection lacquer out of the socket in the set screw
(N) above the pump switch in the actuator assembly using an awl.
c. Using an Allen wrench with a 5/64" hex, turn the screw 1/4 turn:
- clockwise (if the “Pump Off” point is too
high when viewed from top)
- counterclockwise (if the “Pump Off” point
is too low when viewed from top)
5d. Slowly drain the water in the boiler until the pump turns on.
Allow pump to fill the boiler and observe the point on the ruler
where the water level shuts off.
5e. Repeat steps 5a. through d. as necessary to match the
specified Pump Off point specification.
f. Apply one drop of adhesive (furnished) to the set screw threads
(O) above the pump switch in the actuator assembly.
PUMP OFF
PUMP ON
BURNER
“CUT-OFF LEVEL”
AT CAST LINE
5a. Slowly drain the water in the boiler until the
pump turns on. Allow pump to fill the boiler
and observe the point on the ruler where the
water level shuts off.
5 - Setting the Operating Points of the Pump Switch
IMPORTANT: Where Pump On/Off and Burner On/Off are referenced in these instructions, Pump #1 On/Off
and Pump #2 Off/On should be substituted, respectively, for a 159S control, and Motorized Valve
Open/Closed can substitute for Pump On/Off for a 158S control.