Wiring connections, Proportional control, low water cut-off and alarm – Xylem MM 404J Series 93/193 and Series 94/194 Low Water Cut-Off/Pump Controllers For Steam Boilers and Level Control Applications User Manual
Page 9
10
A
SWITCH
COVER
a. Remove two screws (A) and lift off switch
cover.
b. Connect BX armored cable or Thinwall electrical
metal tubing to the integral fitting hub. Connect
wires to terminals following appropriate wiring
diagram from pages 8 and 9 for your application.
NOTE: Follow local codes and standards when
selecting the types of electrical fittings and conduit
to connect to control.
A
SWITCH
COVER
c. Replace switch cover and fasten with two
screws (
A).
Wiring Connections
9
TO BURNER
LINE
1
3
4
4
3
2
1
COMMON
CLOSING CIRCUIT
OPENING CIRCUIT
NO. 7B
SWITCH
BLUE
RED
Proportional Control, Low Water Cut-Off and Alarm
2
4
1
3
BLUE
BURNER ON–ALARM OFF
VALVE CLOSED
BURNER ON–ALARM OFF
VALVE OPEN
BURNER OFF–ALARM ON
VALVE OPEN
RED
3
1
4
2
4
1
3
BLUE
RED
3
1
4
2
4
1
3
BLUE
RED
3
1
4
NOTE: The 7B switch is a 135 ohm potentiometer slide
wire control for use with an electric valve operator with
the same rating.
For Series 93/193 or 94/194 with 7B or 7B-M
Red terminals 1 and 2 are the burner circuit contacts, terminals 3 and 4 are the low level alarm circuit
contacts.
Blue terminal 3 is the common contact, terminals 1 and 4 are the output contacts.