Operation – Xylem MM 235E Replacement Snap Switch Assembly SWA 150S 150S MD 158S 159S User Manual
Page 4
4
Approximate
Distance Above
Cast Line
Differential
Setting
In. (mm)
In. (mm)
Motorized
15
/
16
(24)
Valve Closed
5
/
16
(8)
Motorized
5
/
8
(16)
Valve Open
Burner On
5
/
8
(16)
3
/
8
(16)
Burner Off
1
/
4
(6.4)
Motorized
1
3
/
8
(41)
3
/
4
(19)
Valve Closed
Motorized
5
/
8
(16)
Valve Open
Burner On
7
/
8
(22)
7
/
8
(22)
Burner Off
0
(0)
BURNER
“CUT-OFF LEVEL”
AT CAST LINE
BURNER OFF
BURNER ON
7
/
8
"
DIFFERENTIAL
(22mm)
MOTORIZED
VALVE
CLOSED
BURNER
OFF
BURNER
“CUT-OFF LEVEL”
AT CAST LINE
NORMAL BOILER
WATER LINE
1
3
/
8
"
DIFFERENTIAL
(35mm)
MOTORIZED
VALVE
CLOSED
MOTORIZED
VALVE
OPEN
3
/
4
"
DIFFERENTIAL
(19mm)
NOTE: Due to the slower operation of some
motorized valves, complete valve opening
or closing will occur at slightly different lev-
els than indicated above.
Model 158S
150 psi (10.5 kg/cm
2
) Levels
0 psi
(0 kg/
cm
2
)
150 psi
(10.5 kg/
cm
2
)
Pressure
Operation
Settings and Differential Pressures (continued)
150 psi
(10.5 kg/
cm
2
)
MOTORIZED
VALUE
OPEN
CLOSED
3
/
4
"
DIFFERENTIAL
(19mm)
MOTORIZED
VALVE
CLOSED
BURNER
OFF
NORMAL BOILER
WATER LINE
1
13
/
16
"
DIFFERENTIAL
(46mm)
BURNER CUT-OFF LEVEL
3
/
8
" (9.5mm) BELOW
CAST LINE
Approximate
Distance Above
Cast Line
Differential
Setting
In. (mm)
In. (mm)
Pump Off
15
/
16
(24)
3
/
8
(16)
Pump On
9
/
16
(14)
Burner Off
0
(0)
N/A
Pump Off
1
7
/
16
(37)
3
/
4
(19)
Pump On
11
/
16
(17)
Burner Off
-
3
/
8
(-16)
N/A
Model 158S-MD
0 psi
(0 kg/
cm
2
)
Pressure
150 psi (10.5 kg/cm
2
) Levels
NOTE: Due to the slower operation of some
motorized valves, complete valve opening
or closing will occur at slightly different lev-
els than indicated above.