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System Operation, Testing, and Maintenance
6.2
Maintenance and Component Operation
6.2.1 Electric Panel
The electric panel should be inspected on a semi-annual basis for any loose electrical connections.
6.2.2 Filters
Filters are usually the most neglected item in an environmental control system. In order to maintain efficient operation, they should be checked monthly and changed as required. ALWAYS TURN
POWER OFF BEFORE REPLACING FILTERS.
Filters are replaced by opening the hinged door on the return air filter box.
6.2.3 Blower System
Monthly inspection of the blower package includes: motor mounts, belts, fan bearings, and impellers.
Fan impellers should be thoroughly inspected and any debris removed. Check to see if they are tightly mounted on the fan shaft and do not rub against the fan housing during rotation. Motor and fan bearings are permanently sealed and self-lubricating and do NOT need lubricated.
The drive belt should be checked monthly for signs of wear and proper tension. Pressing on belts midway between the sheave and pulley should produce from 1/2" to 1" (12 to 25 mm) of deflection. Belts that are too tight can cause excessive bearing wear.
Belt tension can be adjusted by raising or lowering the fan motor base. Loosen nut above motor mounting plate to remove belt. Turn nut below motor mounting plate to adjust belt tension. If belt appears cracked or worn, it should be replaced with a matched belt (identically sized). With proper care, a belt should last several years.
NOTE
After adjusting or changing the belt, always be certain that motor base nuts are tightened. The bottom adjustment nut should be finger tight. The top locking nut should be tightened with a wrench.
Air Distribution
Since all unit models are designed for constant volume air delivery, any unusual restrictions within the air circuit must be avoided. High efficiency filters can reduce air performance and evaporator capacity.
Blower Removal (Evaporator)
If the blower or bearings must be removed or serviced, use the following procedure.
1. Prepare the main center section of the three (3) piece electric panel by first marking and disconnecting all power and control wiring entering the panel.
2. Remove the electric panel by removing screws from top and bottom sections
3. Remove the bottom electric panel mounting flange from unit base.
4. Remove the belt, motor, motor mounting plate, and tensioning bolt.
5. Remove the four (4) screws holding the blower mounting rails to the sled.
!
CAUTION
Protect refrigerant and water piping from damage.
6. Remove the (4) screws holding the blower mounting rails to the sled.
7. Slide the blower/rail assembly forward and rotate approximately 45 degrees and remove from unit.
8. Replace failed parts.
51
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Table of contents
- 9 DX Evaporator Section
- 9 Chilled-Water Model
- 9 Air-Cooled Condensing Unit (Indoor Centrifugal)
- 9 Air-Cooled Condensing Unit (Outdoor Prop Fan)
- 9 Water/Glycol Condensing Unit (Indoor)
- 14 Figure 1 System configurations-air cooled systems
- 14 Figure 2 System Configurations-water/glycol systems
- 15 Figure 3 System Configurations-chilled water systems
- 17 Figure 5 Close coupled installation
- 18 Filter Box
- 18 Connections for Ducted Systems
- 18 Table 5 Evaporator external static pressure (60) at 3750 CFM (6371 CMH)
- 19 Drain Line
- 19 Figure 6 Drain installation
- 20 Condensate Pump
- 20 Figure 7 Condensate pump installation
- 20 Humidifier Water Supply Line
- 21 Chilled-Water Piping-Chilled-water Systems Only
- 21 Figure 8 General arrangement diagram - chilled-water systems
- 22 Refrigerant (R-22) Piping
- 22 Table 6 Recommended refrigerant line sizes
- 22 Figure 9 Refrigerant piping diagram
- 23 Total refrigerant = Units and Lines
- 23 Table 7 8-ton unit refrigerant charge
- 23 Table 8 Line charges (field piping)*
- 23 Quick Connect Fittings
- 23 Table 9 Refrigerant quick connect sizes and torque
- 24 Figure 10 Evaporator or chilled-water unit dimensional data
- 25 Power Connections
- 25 Control Connections (10-wire on air-cooled, 8-wire on water/glycol cooled)
- 26 Figure 11 Evaporator unit electrical connections
- 27 General Considerations
- 27 Considerations for Specific Applications
- 28 Figure 12 Piping connections - indoor air-cooled centrifugal fan condensing unit
- 28 Power Connections
- 28 Control Connections
- 29 Figure 13 Indoor air-cooled centrifugal condensing unit dimensions and pipe connections
- 30 Figure 14 Indoor air-cooled centrifugal condenser electrical connections
- 31 Power Connections
- 31 Control Connections
- 32 Figure 15 Electrical field connections - outdoor condensing unit
- 33 Figure 16 Footprint dimensions - outdoor condensing unit
- 34 Figure 17 Piping and electrical connections - outdoor condensing unit
- 35 Water/Glycol Piping Considerations
- 35 Condensing Unit Fluid Requirements
- 35 Regulating Valve
- 35 Control Connections
- 36 Figure 18 Indoor water/glycol condensing unit dimensional data
- 37 Figure 19 Indoor water/glycol condensing unit electrical field connections
- 38 Figure 20 System piping with indoor water/glycol-cooled condensing unit
- 39 Figure 21 Optional free cooling coil (3-way valve) on water/glycol units
- 40 Figure 22 Optional free cooling coil (3-way valve) on air-cooled units
- 47 Table 12 Setup functions, default values and allowable ranges
- 49 Table 14 Equipment switch settings (unit control board)
- 49 Table 15 Switch settings (wallbox board)
- 51 Figure 24 Control menu
- 52 Figure 25 Control board (inside evaporator)
- 52 Figure 26 Wall box board
- 54 System Activation
- 55 Air-Cooled Systems
- 55 Water/Glycol Systems
- 59 Air Distribution
- 59 Blower Removal (Evaporator)
- 60 Suction Pressure
- 60 Discharge Pressure
- 60 Table 16 Typical discharge pressures
- 60 Thermostatic Expansion Valve
- 60 Air-Cooled Condensing Units
- 60 Coaxial Condensers (Water/Glycol-Cooled Condensing Units)
- 61 Regulating Valves (Water/Glycol Condensing Units)
- 61 Glycol Solution Maintenance
- 61 Hot Gas Bypass (Optional)
- 62 Replacement Procedures
- 64 Replacing the Humidifier Canister
- 64 Table 17 Humidifier control board DIP switch settings