Honeywell R4795A Manual

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.
S.Y. • Rev. 12-94 • ©Honeywell Inc. 1994
Flame Safeguard
Primary Controls
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.
CONTENTS
Specifications ................................................. 2
Ordering Information ..................................... 2
Installation ..................................................... 4
Checkout ......................................................... 8
Operation ..................................................... 11
Troubleshooting ........................................... 11
Service .......................................................... 13
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R4795A
60-2285-7
60-2285-7