T2 - 80 MINUTE SETTING
T3 - 110 MINUTE SETTING
(Factory Set Point)
T1 - 50 MINUTE SETTING
SHORTING PEGS TO
OVERRIDE TIMER
FOR SERVICE
MOVABLE JUMPER
WIRE TO CHANGE
DEFROST TIMER
FIG. 12 - AMBIENT MODIFIED TIME/TEMPERATURE CONTROL
SECURE OWNER’S APPROVAL: When the system is functioning properly, secure the owner’s approval. Show him the location of all disconnect switches and the thermostat. Teach him how to start and stop the unit and how to adjust temperature settings within the limitations of the system.
MAINTENANCE
NORMAL MAINTENANCE
CAUTION: Prior to any of the following maintenance proce- dures, shut off all electric power to the unit to prevent personal injury.
FILTERS - Inspect once a month. Replace disposable or clean permanent type as necessary. DO NOT replace permanent type with disposable. The dimensional size of the replacement filter must be the same as the replaced filter.
MOTORS
Outdoor fan motors are permanently lubricated and require no maintenance.
Indoor Blower Motor and Drive - The indoor blower motor features ball bearings that do not require periodic lubrication. Periodic lubrication of the motor and bearings can extend the life of components but is optional.
CAUTION: Damage can occur if the bearings are overlubri- cated. Use grease sparingly.
WARNING: Perform all maintenance operations on the blower motor with electric power disconnected from the unit. Do not attempt to lubricate bearings with the unit in operation.
On an annual basis, check the motor for accumulations 
of dust, etc. that may block the cooling slots in the motor shell. Check for loose, damaged or misaligned drive components. Check that all mounting bolts are tight. Replace
defective parts as required.
If desired, every three years remove both pipe plugs at each end shell and clean out any hardened grease or foreign matter. Replace one plug on each end with a clean grease fitting. Using a low pressure grease gun, pump grease (Chevron
On 20 ton only, units are supplied with blower shaft bearings that do not require maintenance but may be relubricated if desired. Every three years, using a low pressure grease gun, pump grease into the bearing grease fitting until grease just begins to show at the seals. Do not over lubricate. Use any lithium base grease recommended for ball bearing service.
OUTDOOR COIL - Dirt should not be allowed to accumulate on the outdoor coil surface or other parts in the air circuit. Cleaning should be as often as necessary to keep coil clean. Use a brush, vacuum cleaner attachment, or other suitable means. If water is used to clean coil, be sure electric power to the unit is shut off prior to cleaning.
NOTE: Exercise care when cleaning the coil so that the coil fins are not damaged.
Do not permit the hot outdoor air discharge to be obstructed by overhanging structures of shrubs.
18 | Unitary Products Group |
