Honeywell C437D - User Manual

PRODUCT DATA
68-0286
C437D,E Gas Pressure Switches
APPLICATION
The C437D,E Gas Pressure Switches are pressure-actuated
switching devices used in industrial gas system applications
for safety shutoff, pressure control, and differential-pressure
control.
All Series 4 models have MicroSwitch™ snap switches to
open or close a circuit on pressure rise or drop.
NOTE: Series numbers immediately follow OS numbers, i.e.,
C437D2003(4).
FEATURES
• C437 models have direct- and reverse-acting (spst)
switching.
• Pressure ranges: 1/2 to 5-1/2 in. of water (0.1 to 1.4
kPa); 1 to 26 in. of water (0.5 to 7 kPa); 1/2 to 5 psi (3 to
35 kPa); 1 to 10 psi (5 to 70 kPa).
• Models intended for lockout applications must be
manually reset before resuming operation.
• Trip-free mechanism on manual reset models ensures
that the limit function of the switch cannot be defeated
by jamming the reset lever.
• External manual reset button on side of lockout
models.
• Enclosed setting impedes tampering and provides
dust-resistant operation.
• Buna-N fiber-reinforced material for increased
strength of control diaphragm.
• Two Buna-N fiber-reinforced seal-off diaphragms for
added reliability.
• Clear glass cover allows observation of interior
mechanism to aid setting and checkout.
• Heavy die-cast case increases durability and
resistance to corrosion.
• Main control diaphragm completely enclosed a leak-
proof chamber can be vented to a safe area.
• Models with a pressure range of 1 to 26 in. of water (0.5
to 7 kPa) have a restrictive orifice in the inlet pressure
channel to compensate for momentary surges in gas
pressure.
• Field-addable orifices of various sizes are available.
Contents
Application ........................................................................ 1
Features ........................................................................... 1
Specifications ................................................................... 2
Ordering Information ........................................................ 2
Installation ........................................................................ 4
Wiring ............................................................................... 5
Setting and Checkout ....................................................... 5

Honeywell C437D Specifications

General

Brand	Honeywell
Model	C437D
Category	Switch
Language	English

Summary

APPLICATION

FEATURES

Switching Capabilities

C437 models feature direct- and reverse-acting (spst) switching for pressure control.

Pressure Range Options

Offers multiple pressure ranges, from 0.1 kPa to 70 kPa, for diverse industrial applications.

Manual Reset and Safety Features

Includes manual reset, trip-free mechanism, and enclosed setting for enhanced safety and tamper resistance.

Durability and Reliability

Features reinforced diaphragms, a leak-proof chamber, and a die-cast case for robust construction.

Observation and Surge Compensation

Clear glass cover for observation and restrictive orifices for surge compensation are included.

SPECIFICATIONS

Model Designations and Switch Actions

Differentiates C437D (breaks on rise) and C437E (breaks on fall) with manual reset functionality.

Electrical Switch Ratings

Lists full load, locked rotor, and resistive load ratings in Amperes for 120 Vac and 240 Vac.

Pressure Differential Specifications

Details nominal pressure differentials for various ranges and model types (subtractive/additive).

Available Pressure Ranges

Lists the scale ranges for pressure, specified in inches of water and psi, with corresponding kPa values.

ORDERING INFORMATION

MAXIMUM OPERATING PRESSURES AND DETAILS

Maximum Sustained Operating Pressure

Table specifying maximum sustained operating pressure limits in psi and kPa for each pressure range.

Pipe Connections and Environmental Limits

Details NPT connection sizes, conduit tapping, and temperature limits for installation.

Approvals, Parts, and Accessories

Lists product approvals, replacement parts, and optional accessories like mounting brackets and orifices.

INSTALLATION

Installation Precautions and Preparation

Stresses reading instructions, checking ratings, and performing initial preparation steps.

Location and Mounting Guidelines

Advises on proper mounting location and procedures, including bracket installation.

Piping Connections and Application Types

Covers main piping, pressure switch connections, and specific requirements for gas/differential applications.

WIRING

Wiring Safety and Compliance

Emphasizes electrical shock prevention and adherence to local codes and switch ratings.

Terminal Connections and Routing

Explains how to connect wiring to the terminal strip and route it through the conduit tapping.

SETTING AND CHECKOUT

Setting Adjustment Procedure

Details how to adjust the setpoint using the setting screw, considering differentials.

Manual Reset and Trip-Free Operation

Describes the function of the manual reset button and the trip-free mechanism for C437D,E models.

Operational Checkout Steps

Guides on verifying switch operation by simulating pressure changes and using the reset button.

COMPLETING INSTALLATION AND ORIFICE INSTALLATION

Final Installation Steps

Covers final checks, cover replacement, and engaging the manual reset for C437D,E.

Installing Pressure Orifice for Surge Control

Explains the procedure for installing a restrictive orifice to mitigate pressure surges.