Honeywell R7795C

1 66-2001—2 B. M. • Rev. 9-93 • ©Honeywell Inc. 1993 • Form Number 66-2001—2
R7795A,B,C,D
Flame Safeguard
Primary Controls
The R7795 Flame Safeguard Primary Control
provides flameout protection plus automatic
control of commercial and industrial gas and
oil burners. Models provide intermittent pilot
or interrupted pilot with delayed main valve.
CONTENTS
Specifications .................................................2
Ordering Information.....................................2
Detailed Operating Sequence ........................4
Installation .....................................................8
Checkout.......................................................11
Troubleshooting ...........................................17
Service ..........................................................19
■ Field selectable ten or four second trial for pilot
flame ignition.
■ Powered alarm terminal to operate an external line
voltage alarm on safety lockout.
■ R7795 models are available with either intermittent
pilot (interrupted ignition) or interrupted pilot and
delayed main valve. See Table 2.
■ Run-Test switch on interrupted pilot/delayed main
valve models.
■ Safe-start feature prevents start-up with lockout if
flame or a flame simulating failure exists.
■ Recycle or lockout on flame failure is field selectable.
■ Safety switch must be manually reset after lockout.
■ Meets Underwriters Laboratories, Canadian Stan-
dards Association, and Factory Mutual Approved
standards.
■ Integral solid state color-coded flame amplifiers:
R7795A,C for ultraviolet detection systems (purple).
R795B,D for rectification detection systems (green).
See Table 1.
■ Solid state plug-in ST95A Purge Timers provide
prepurge timings of 1.5, 7, 10, 30, 60, or 90 seconds.
■ Includes terminals for connection of a line voltage
airflow switch to prove airflow from the start of
prepurge through the run period.
■ Mounts on a Q795A Subbase with two captive
screws. All electrical connections are automatically
provided between the device and subbase. Wiring
terminals are accessible for testing.
■ Meter jack on amplifier board for measuring flame
signal with system in operation.
■ Internal light-emitting diode (LED) indicates pres-
ence of flame signal.

Honeywell R7795C Specifications

General

Brand	Honeywell
Model	R7795C
Category	Control Unit
Language	English

Summary

Specifications

Electrical and Terminal Ratings

Details on voltage, frequency, power consumption, and terminal load capacities.

Physical, Mounting, and Approval Details

Information on operating environment, physical size, weight, mounting, and certifications.

Compatible Accessories

List of optional and compatible accessories for the R7795.

Ordering Information

Detailed Operating Sequence (Intermittent Pilot)

Detailed Operating Sequence (Interrupted Pilot)

Installation

Subbase Mounting and R7795 Installation

Instructions for mounting the Q795A Subbase and installing the R7795 control unit.

Wiring Hookups

Typical wiring connections to the Q795A Subbase for R7795 models.

Wiring Diagrams

Illustrative diagrams showing R7795 wiring for different model types.

Checkout Procedures

Required Equipment and Initial Inspection

List of necessary tools and initial checks before performing R7795 tests.

Flame Signal Measurement and Pilot Lightoff

Measuring flame signal, performing initial lightoff for proved pilot and oil ignition.

Pilot Turndown and Ignition Interference Testing

Testing pilot flame stability and checking for ignition spark interference.

Response and Shutdown Safety Tests

Tests for hot refractory hold-in, UV response, and safe shutdown functions.

Flame Failure and Power Failure Tests

Procedures for testing flame failure response and system behavior during power loss.

Troubleshooting

Preliminary Inspection and Trouble List

Initial system checks and identification of common operational problems.

Troubleshooting Procedures by Symptom

Detailed steps to diagnose and resolve specific issues based on symptom.

Service

General Service and Maintenance

Guidelines for qualified personnel performing service and periodic maintenance.

Contact Cleaning Procedures

Safe and proper methods for cleaning R7795 control contacts.