2.4

Wiring

Caution: Level controls are shipped from the factory with the enclosing

tube tightened and the middle set screw, on the housing

base, locked to the enclosing tube. Failure to loosen the set

screw prior to repositioning the conduit connection may

cause the enclosing tube to loosen, resulting in the possible

leakage of the process liquid or vapor.

Most B40 level control switch housings are designed to

allow 360° positioning of the conduit outlet by loosening

the set screw(s) located under the housing base. High

temperature wire must be used between control and first

junction box located in a cooler area.

NOTE: A switch or circuit breaker shall be installed in close proximity

to equipment and within easy reach of operator. It shall be

marked as the disconnecting device for equipment.

1. To gain access to switch mechanism, remove switch

housing cover.

2. Pull in supply wires (conductors), wrap them around

enclosing tube under the baffle plate and connect to

proper terminals. Be certain that excess wire does not

interfere with tilt of switch, and that adequate clearance

exists for replacement of switch housing cover.

NOTE: For supply connections in installations with ambient tempera-

ture up to +70° C, use wire with a minimum rating of +75° C as

required by process conditions. Installations with ambient

temperatures up to +80° C require wire with a minimum rating

of +85° C as required by process conditions. Use a minimum of

14 AWG wire for power and ground field wires.

NOTE: See Figure 4 or bulletin on switch mechanism furnished for

proper terminal connections. Switch bulletin numbers are

listed in the chart below.

3. Connect power supply to control and test switch action

by varying liquid level in float chamber. If switch

mechanism fails to function, check vertical alignment

of control and consult installation instructions in switch

mechanism bulletin.

6

46-602 B40 Liquid Level Switches

Internal Circuit

(Right) Switch

1

2

3

Load

Load

Close on low level

Common

Close on high level

Line

4

5

6

Internal Circuit

(Left) Switch

Load

Load

Close on low level

Common

Close on high level

Line

Figure 4

Switch

Series

Letter

Description

Bulletin

No.

A

Standard Mercury Switch

42-683

3, L

Mercury Switch w/Beaded Leads

C, D, S

Dry Contact Switch

2, E, L

Vibration Resistant Mercury Switch

F

Hermetically Sealed Snap Switch

HS

Hermetically Sealed Snap Switch

42-694

R

High Temperature Snap Switch

42-799