Compressor Crankcase Heaters; Main Unit Display And Reliatel Controls; Field-Installed Control Wiring; Control Power Transformer - Trane Horizon OABD Series Installation, Operation And Maintenance Manual

Compressor Crankcase Heaters

WARNING
Live Electrical Components!
Failure to follow all electrical safety precautions when
exposed to live electrical components could result in
death or serious injury. When it is necessary to work
with live electrical components, have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks.
AVERTISSEMENT
Composants électriques sous tension!
Le non-respect de toutes les consignes de sécurité lors
de la manipulation de composants électriques sous
tension peut entraîner des blessures graves, voire
mortelles. S'il est nécessaire de travailler avec des
composants électriques sous tension, demandez à un
électricien qualifié et agréé ou à une autre personne
ayant la formation nécessaire pour manipuler des
composants électriques sous tension d'exécuter ces
tâches.
To prevent injury or death from electrocution, it is the
responsibility of the technician to recognize this hazard and
use extreme care when performing service procedures with
the electrical power energized.
Each compressor shall be equipped with a crankcase heater.
The proper operation of the crankcase heater is important to
maintain an elevated compressor oil temperature during the
"Off" cycle to reduce oil foaming during compressor starts. Oil
foaming occurs when refrigerant condenses in the compressor
and mixes with the oil. In lower ambient conditions, refrigerant
migration to the compressor could increase.
When the compressor starts, the sudden reduction in
crankcase pressure causes the liquid refrigerant to boil rapidly
causing the oil to foam. This condition could damage
compressor bearings due to reduced lubrication and could
cause compressor mechanical failures.
Before initial start up, or if main power has been off for an
extended period of time, compressor crankcase heater(s)
should be operated for a minimum of 8 hours prior to
compressor operation. With main power OFF, remove jumper
between OAUTS terminals 9 and 10 (E-Stop). Turn main
power to energize crankcase heater(s). At end of warm up
period turn main power off, install 9-10 jumper, turn main power
on, and resume normal operation.
Following crankcase heater warm-up, turn main power
disconnect off, and install jumper on E-Stop terminals 9 and 10.
Turn Main disconnect "On".

Main Unit Display and ReliaTel Controls

When first powered "On", the controls perform self-diagnostic
initialization to check that all internal controls are functional.
OAU-SVX007A-EN
The Status LED located on the Main Unit Display and the
Liteport LED located on the RTRM module is turned "On"
within one second of power-up if internal operation is okay.

Field-Installed Control Wiring

WARNING
Proper Field Wiring and Grounding
Required!
Failure to follow code could result in death or serious
injury. All field wiring MUST be performed by qualified
personnel. Improperly installed and grounded field
wiring poses FIRE and ELECTROCUTION hazards. To
avoid these hazards, you MUST follow requirements for
field wiring installation and grounding as described in
NEC and your local/state/national electrical codes.
ATTENTION
Câblage et Mise à la Terre Appropriés
Champs Obligatoires!
Le non-respect du code pourrait entraîner la mort ou
grave blessure. Tout le câblage sur le terrain DOIT être
effectué par des personnes qualifiées personnel.
Terrain mal installé et mis à la terre le câblage pose des
risques de FIRE et d'ÉLECTROCUTION. À evitez ces
risques, vous devez suivre les exigences pour
l'installation et la mise à la terre du câblage de terrain
comme décrit dans NEC et vos codes électriques
locaux/étatiques/nationaux.
An overall layout of the various control options available with
the required number of conductors for each control device is
illustrated in Figure 142, p.
Note: All field wiring must conform to NEC guidelines as well
as state and local codes.

Control Power Transformer

WARNING
Hazardous Voltage!
Failure to disconnect power before servicing could
result in death or serious injury. Disconnect all electric
power, including remote disconnects before servicing.
Follow proper lockout/tagout procedures to ensure the
power can not be inadvertently energized.Verify that no
power is present with a voltmeter.
Installation
89.
87