Vent; Changing Controller Action Or Mode; Throttling And On/Off Controllers; Snap-Acting Controller - Emerson Fisher L2 Instruction Manual

L2 Controller
July 2015

Vent

WARNING
If a flammable or hazardous gas is to be used as the supply pressure medium, personal injury or property damage could
result from fire or explosion of accumulated gas or from contact with hazardous gas. The controller/actuator assembly
does not form a gas‐tight seal, and when the assembly is enclosed, a remote vent line, adequate ventilation, and necessary
safety measures should be used. However, a remote vent pipe alone cannot be relied upon to remove all hazardous gas.
Vent line piping should comply with local and regional codes and should be as short as possible with adequate inside
diameter and few bends to reduce case pressure buildup.
The vent opening or the end of the remote vent pipe, if one is required, must be protected against the entrance of all
foreign matter that could plug the vent. Use 13 mm (1/2‐inch) diameter pipe for the remote vent pipe. Check the vent
periodically to be certain it is free of any obstructions.

Changing Controller Action or Mode

WARNING
To avoid personal injury caused by a sudden release of pressure, shut off the supply pressure and bleed pressure from the
supply lines before performing any procedure in this section.
Throttling and On/Off Controller
The action of a throttling and on/off controller may be changed between either direct or reverse, and the control
mode may be changed between either on/off or throttling.
Refer to figure 3. Loosen the four switch retention screws on the relay. Move the switches to the control action and
control mode required by the application. Tighten the four switch retention screws.
Snap‐Acting Controller
The action of a snap‐acting controller may be changed between either direct or reverse. The control mode is always
snap acting.
Refer to figure 4. Loosen the four switch retention screws on the relay. Move the switches to the control action
required by the application. Tighten the four switch retention screws.
6
Instruction Manual
D103032X012