Service - Carrier 50HJQ014 Installation, Start-Up And Service Instructions Manual

Staging should be as follows:
If Heating PID STAGES=2
• HEAT STAGES=1 (75% capacity) will energize HS1
• HEAT STAGES=2 (100% capacity) will energize HS2
In order to prevent short cycling, the unit is locked into the
Heating mode for at least 10 minutes when HS1 is deenergized.
On units equipped for two stages of heat, when additional heat
is needed, it may be provided by electric heat (if supplied).
When the space condition is satisfied and HS1 is deenergized
the IFM stops. The fan will run continuously in the occupied
mode as required by national energy and fresh air standards.
DEFROST — When the temperature of the outdoor coil drops
below 28 F as sensed by the defrost thermostat (DFT2) and the
defrost timer is at the end of a timed period (adjustable at 30,
50, or 90 minutes), reversing valve solenoids (RVS1 and
RVS2) are energized and the OFC is deenergized. This switch-
es the position of the reversing valves and shuts off the outdoor
fan. The electric heaters (if installed) will be energized.
The unit continues to defrost until the coil temperature as
measured by DFT2 (see Fig. 43) reaches 65 F, or the duration
of defrost cycle completes a 10-minute period.
During the Defrost mode, if circuit 1 defrosts first, RVS1
will oscillate between Heating and Cooling modes until the
Defrost mode is complete.
At the end of the defrost cycle, the electric heaters (if
installed) will be deenergized; the reversing valves switch and
the outdoor-fan motor will be energized. The unit will now
operate in the Heating mode.
If the space thermostat is satisfied during a defrost cycle, the
unit will continue in the Defrost mode until the time or temper-
ature constraints are satisfied.
DEFROST
THERMOSTAT
NOTE: Defrost thermostat is located at the bottom tee of circuit
no. 1 and the top tee of circuit no. 2.
Fig. 43 — Defrost Thermostat Location

SERVICE

Before performing service or maintenance operations on
unit, turn off main power switch to unit. Turn off accessory
heater power switch if applicable. Electrical shock could
cause personal injury.
Cleaning —
Inspect unit interior at beginning of each heat-
ing and cooling season and as operating conditions require.
Remove unit top panel and/or side panels for access to unit
interior.
INDOOR COIL — Clean as required with a commercial coil
cleaner.
OUTDOOR COIL — Clean outdoor coil annually and as
required by location and outdoor-air conditions. Inspect coil
monthly — clean as required.
CONDENSATE DRAIN — Check and clean each year at
start of cooling season.
FILTERS — Clean or replace at start of each heating and cool-
ing season, or more often if operating conditions require. Refer
to Table 1 for type and size.
OUTDOOR-AIR INLET SCREENS — Clean screens with
steam or hot water and a mild detergent. Do not use throwaway
filters in place of screens.
Lubrication
COMPRESSORS — Each compressor is charged with the
correct amount of oil at the factory. Observe the level in the
sight glass immediately after shutdown while the oil is still
warm. If the oil level is observed when the oil is cold, the level
observed may be a mixture of oil and refrigerant which is not a
true indication of the oil level. If oil level observed is not be-
tween the low limit and high limit levels as indicated in Fig. 44,
add oil until it is in the correct range.
Fig. 44 — Compressor Sight Glass Oil Level
FAN SHAFT BEARINGS — For size 014 units, bearings are
permanently lubricated. No field lubrication is required. For
size 016 units, the bearings are of the pillow block type and
have grease fittings. The bearing opposite the motor end has an
extended tube line so it can be lubricated from the motor side.
Lubricate the bearings twice annually.
Typical lubricants are given below:
MANUFACTURER
Texaco
Mobil
Sunoco
Texaco
*Preferred lubricant because it contains rust and oxidation inhibitors.
OUTDOOR AND INDOOR-FAN MOTOR BEARINGS —
The outdoor and indoor-fan motors have permanently sealed
bearings, so no field lubrication is necessary.
Indoor Fan, 50HJQ014 Units
PERFORMANCE ADJUSTMENT — Fan motor pulleys on
the 50HJQ014 units are factory set for speed shown in Table 1.
To change fan speeds:
1. Shut off unit power supply.
2. Loosen belt by loosening fan motor mounting plate nuts.
3. Loosen movable-pulley flange setscrew (see Fig. 45).
4. Screw movable flange toward fixed flange to increase
speed and away from fixed flange to decrease speed. In-
creasing fan speed increases load on motor. Do not ex-
ceed maximum speed specified in Table 1.
5. Set movable flange at nearest keyway of pulley hub and
tighten setscrew.
31
LUBRICANT
Regal AFB-2*
Mobilplex EP No. 1
Prestige 42
Multifak 2