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

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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.

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