Startup
RRU-SVX01F-EN
35
7. Check the compressor oil levels. The oil level in each
compressor sight glass should be 1/2 to 3/4 full when
they are “Off”.
8. After the compressor and condenser fan have started
and operated for approximately 30 minutes, observe
the operating pressures. Compare the operating
pressures to the operating pressure curve in the
Service Facts.
9. Check system superheat. Follow the instruction listed
on the superheat charging curve in the Service Facts.
Superheat should be within ±5°F of the superheat chart
value.
10. Repeat
for each refrigerant
circuit.
Direct Gas-Fired Heating Startup
Notes:
•
BEFORE OPERATING, leak test all gas piping up to
heater gas valve. Smell around the unit area for gas. If
gas is smelled, do NOT attempt to place heater in
operation until source of gas leak is identified and
corrected.
•
Use only hand force to operate the gas control lever to
the “ON” position. NEVER use tools. If lever does not
operate by hand, replace gas valve prior to staring the
unit. Forcing or attempting to repair the gas valve may
result in fire or explosion.
•
Do not attempt to operate unit, if there is indication that
any part or control has been under water. Any control
or component that has been under water must be
replaced prior to trying to start the unit.
Refer to
“Sequence of Operation,” p. 19
for additional
information.
The following procedure must be followed for the unit
heating section to function properly. The following
procedures are to be performed after all electrical and gas
connections to the unit have been completed and the
outdoor air damper and evaporator fan operation have
been verified and are operating satisfactorily.
Refer to
“Sequence of Operation,” p. 19
for additional
information.
Tools Required
•
Voltage meter (µA)
•
Amp meter
•
Gas pressure gauge
•
Tachometer
•
Temperature probe
•
Anemometer
•
Service mirror
•
Small refrigeration screwdriver
•
5/16-in. Nut driver
•
1/2-in. Open end wrench
1. Confirm Unit Airflow
Important:
Accurate airflow readings require clean
inlet filters. If required clean or replace
filters before proceeding.
All Horizon direct gas-fired heaters are factory-
adjusted to achieve design airflow pressure drop (
P)
of -0.625 in. wc across the burner profile opening at
ordered unit SCFM airflow. The burner baffles should
not be adjusted. Outdoor Air conditions will cause the
measured
P to vary. Refer to
acceptable measured pressures that may be read at
various outdoor air conditions. Measure and record
burner pressure drop.
WARNING
Hazardous Service Procedures!
Failure to follow all precautions in this manual and on
the tags, stickers, and labels could result in death or
serious injury.
•
Technicians, in order to protect themselves from
potential electrical, mechanical, and chemical
hazards, MUST follow precautions in this manual and
on the tags, stickers, and labels, as well as the
following instructions: Unless specified otherwise,
disconnect all electrical power including remote
disconnect and discharge all energy storing devices
such as capacitors before servicing. Follow proper
lockout/tagout procedures to ensure the power can
not be inadvertently energized. When necessary to
work with live electrical components, have a
qualified licensed electrician or other individual who
has been trained in handling live electrical
components perform these tasks.
•
Do not attempt the following procedures until all
electrical and gas connections to the unit have been
completed and the outdoor air damper and
evaporator fan operation have been verified and are
operating correctly.
WARNING
Hazard of Explosion!
Failure to follow safe leak test procedures below could
result in death or serious injury or equipment or
property-only-damage.
Never use an open flame to detect gas leaks. Use a leak
test solution for leak testing.
