Start-Up; Verify Indoor Fan Operation; Compressor Start-Up - Trane RRU150F N Series Installation, Operation And Maintenance Manual

Start-Up

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.

Verify Indoor Fan Operation

At unit ROD override indoor fan OFF. Bring unit to occupied
mode using unit control or jumper at RRUTS Terminals 7–
8. At 90 seconds after occupied signal is made, unit
operation will stop if indoor fan airflow does not prove the
Fan Failure Switch. After successful confirmation, release
indoor fan override. (Fan Failure Switch is located on the
supply plenum wall in the evaporator section.)
Note: Unit operation will stop after 10 minutes of indoor
fan operation if the discharge air sensor is not
connected properly to the RRUTS.

Compressor Start-Up

1. Attach a set of service gauges onto the suction and
discharge gauge ports for each circuit. Refer to the
refrigerant circuit illustration in the Service Facts.
2. Override binary output for Y1 and Y2 and check each
compressor circuit by selecting Cooling Stage 1 – Y1
or Cooling Stage 2 – Y2.
Scroll Compressors
3. Once each compressor has started, verify that the
rotation is correct. If a scroll compressor is rotating
backwards, it will not pump and a loud rattling sound
can be observed.
34
4. If the electrical phasing is correct, before condemning
a compressor, interchange any two leads (at the
compressor Terminal block) to check the internal
phasing. Refer to the following illustration for the
compressor terminal/phase identification. If the
compressor runs backward for an extended period
(15 to 30 minutes), the motor winding can overheat and
cause the motor winding thermostat to open.
5. 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".
6. 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.
7. 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.
8. Repeat Step 1 through
circuit.
Step 7 for each refrigerant
RRU-SVX02F-EN