Honeywell R4795A, Manual, Page: 1 / 16

1 60-2285—7
R4795A
Flame Safeguard
Primary Controls
The R4795A Protectorelay™ Primary Control
provides solid state electronic flame safeguard
protection for commercial and industrial gas or oil
burners. It provides a prepurge period before each
start, and intermittent pilot.
■
120V models meet the requirements of Underwrit-
ers Laboratories Inc. Standard 795 for mechanical
draft and atmospheric burner inputs from 400,000 to
2,500,000 Btu.
■
Meets Underwriters Laboratories Inc. requirements
for oil burner group 8 when 30, 60, or 90 second pre-
purge timer is used.
■
Selection of solid state, plug-in prepurge timers pro-
vides 7, 10, 30, 60, or 90 second prepurge time.
■
Includes terminals for connection of air flow switch
to prove airflow before prepurge period starts, dur-
ing purge, and during the entire Run period.
■
Choice of interchangeable, color-coded, solid state,
plug-in flame signal amplifiers allows use with rec-
tification or ultraviolet type flame detectors.
■
Safe-start feature prevents start when flame or flame
simulating condition is present.
■
Recycles through prepurge if the flame goes out
while burner is running. If pilot flame is not re-
established, safety switch trips and locks out system.
■
A tripped safety switch must be manually reset to
restore operation.
■
Push-to-reset safety switch is dust-resistant enclosed.
■
Optional spdt alarm contacts operate external alarm
on safety switch lockout.
■
Ignition interference circuit (rectification amplifier
only) protects electronic network from high voltage
ignition crossover and provides visual indication
when interference occurs.
■
Solid state circuitry eliminates vacuum tube replace-
ment and increases resistance to vibration. Applica-
tion of power not required during Off cycle; no tube
warmup before starting.
■
Easy-to-replace plug-in components result in faster
service and reduced inventory.
■
Flame current jack, located on the amplifier, provides
means of plugging in a microammeter to measure the
flame signal with system operating.
■
Easy mounting and removal through use of captive
mounting screws, which also serve as electrical
connections.
■
Durable thermoplastic mounting base.
■
Models available with -40 ° F (-40 ° C) temperature
rating.
S.Y. • Rev. 12-94 • ©Honeywell Inc. 1994
60-2285-7
CONTENTS
Specifications ................................................. 2
Ordering Information ..................................... 2
Installation ..................................................... 4
Checkout ......................................................... 8
Operation ..................................................... 11
Troubleshooting ........................................... 11
Service .......................................................... 13