How to Guide

Commercial Pressure and Float Switches for Power Circuits

Electromechanical Pressure Switches, Class 9013 Types F and G

03/2011

Electromechanical Pressure Switches,

Class 9013 Types F and G

Introduction

The Pumptrol Class 9013 Type F commercial pressure switches are UL Listed and CSA certified as

commercial control equipment. Type G pressure switches are UL Listed and CSA certified as

commercial / light industrial control equipment.

The Type FHG compressor pressure switch is used to control electrically driven air compressors. It is

diaphragm actuated, and its contacts open on rising pressure.

The Type FSG, FTG, FYG, and FRG water pump pressure switches are used to control electrically

driven water pumps. They are diaphragm actuated.

• The Type FSG standard water pump switch is suitable for all types of pumps, including jets,

submersible, and reciprocating.

• The Type FTG fixed differential water pump switch is suitable for all types of pumps, including jets,

submersible, and reciprocating. It is an ideal choice for OEM markets. Minimum quantity

restrictions apply.

• The Type FYG is designed to meet higher horsepower and pressure requirements.

• The Type FRG is reverse acting: the contacts open on falling pressure.

The Type G commercial / light industrial pressure switch is used to control electrically driven water

pumps and air compressors. It has higher electrical ratings for direct control of motors in pump and

compressor applications. The Type G switch is diaphragm actuated, and its contacts open on rising

pressure.

Setting Points

Every pressure switch has two setting points: one on rising pressure and one of falling pressure. For

pumps and compressors, the setting point on rising pressure is called the trip point or cut-out; the

setting point on falling pressure is called the reset point or cut-in.

Differential

The differential is the difference in pressure between the trip point (cut-out) and the reset point (cut-in).

It can be adjustable or fixed. Example—Cut-in (30 psi) / Cut-out (50 psi): Differential = 20 psi

Range

The range indicates the pressure limits within which the settings can be adjusted. The range is

referenced to the setting point on rising pressure (trip point). The differential subtracts from the trip

point setting. When using a diaphragm-actuated switch, system pressure during the normal operating

cycle should never exceed the upper limit of the range. Excessive pressure will greatly reduce the life

of the diaphragm.

Maximum Allowable Pressure

Maximum allowable pressure is the pressure to which a switch can be subjected without causing a

change in operating characteristics, shift in settings, or damage to the device. Pressure surges may

occur in a system during the start up of a machine or from valve operation. Surges are not normally

detrimental to the life of a switch if the surge is within the maximum allowable pressure rating of the

switch. Diaphragm-actuated switches should not be subjected to more than 10 surges per day. More

frequent surges will greatly reduce the life of the diaphragm.