Xylem MM 235E Replacement Snap Switch Assembly SWA 150S 150S MD 158S 159S - Manual (Page 6)

PUMP
SWITCH
PUMP
CIRCUIT
TERMINALS
LOW WATER
CUT-OFF AND
ALARM SWITCH
ALARM
CIRCUIT
TERMINALS
LOW WATER
CUT-OFF
TERMINALS
6
3. Remove the cover (B).
4. Mark and remove the pump switch and
burner/alarm switch wires from terminal block.
1. Turn the boiler off.
A
2. Allow the boiler to cool to 80˚F (27˚C) and
release the boiler pressure to 0 psi (0 bar).
Drain water in the boiler to a level which is
below the float chamber (A).
INSTALLATION
SECTION 1 - Switch Bracket Replacement
• To prevent electrical shock, turn off the electrical power before making electrical connections.
• This low water cut-off must be installed in series with all other limit and operating controls installed on the
boiler. After installation, check for proper operation of all of the limit and operating controls, before leaving
the site.
Failure to follow this warning could cause electrical shock, an explosion and/or a fire, which could result in
property damage, personal injury or death.
! WARNING
B
OFF
ON
Terminal Connection
Product Switch 1 2 3 4 5 6
150S/157S 2 Wire Blue Yellow
Pump
3 Wire Black White Red
Burner
158S 3 Wire Black White Red
Pump
3 Wire Black White Red
Burner
159S 2 Wire Blue Yellow
Pump
2 Wire Blue Yellow
Burner
Terminal Connection Reference Chart