50DJ,DK,DW,DY024-030 Single-Package Cooling Units Installation, Start-Up and Service Instructions CONTENTS Page SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 2 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30 Rigging and Unit Placement . . . . . . . . . . . . . . . . . . 2 Roof Curb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Roof Mount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Slab Mount . . . . . . . . . . .
Refrigerant Feed Components . . . . . . . . . . . . . . . 51 Thermostatic Expansion Valve (TXV) . . . . . . . . . 51 Moisture/Liquid Indicator . . . . . . . . . . . . . . . . . . . . 51 Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Liquid Line Service Valve . . . . . . . . . . . . . . . . . . . . 51 Compressor Discharge Service Valve . . . . . . . . 51 Protective Devices . . . . . . . . . . . . . . . . . . . . . . . . . .
NOTICE TO RIGGERS UNIT 50 DJ,DK024 DW,DY024 DJ,DK028 DW,DY028 DJ,DK030 DW,DY030 WEIGHT lb 2440 2650 2900 3100 2930 3140 kg 1107 1202 1315 1406 1329 1424 A in. 66.14 85.91 77.01 97.24 77.01 97.24 B mm 1680 2182 1956 2470 1956 2470 in. 49 61 53 66 53 66 C mm 1244.6 1549.4 1346.2 1676.4 1346.2 1676.4 NOTES: 1. Rig with 4 cables and spread with two 95 in. (2413 mm) and 2 ‘‘A’’ long suitable spreader bars. 2. Center of gravity and unit weight include economizer. 1.
Table 1A — Physical Data, Constant Volume Units UNIT 50 OPERATING WEIGHT (lb)* COMPRESSORS (2 each unit) Capacity Steps (%) Standard Accessory REFRIGERANT Operating Charge (lb), Circuit 1/Circuit 2 CONDENSER COILS Face Area (sq ft) Fins Per in. Al Cu EVAPORATOR COILS Face Area (sq ft) Fins Per in.
Table 1B — Physical Data, Variable Volume Units UNIT 50 OPERATING WEIGHT (lb)* COMPRESSORS (2 each unit) Capacity Steps (%) REFRIGERANT Operating Charge (lb), Circuit 1/Circuit 2 CONDENSER COILS Face Area (sq ft) Fins Per in. Al Cu EVAPORATOR COILS Face Area (sq ft) Fins Per in.
UNIT LEVELING TOLERANCES NOTE: To prevent the hazard of stagnant water build-up in the drain pan of the indoor-air section, unit can only be pitched as shown. NOTES: 1. Roof curb accessory 50DJ900391 is shipped unassembled. 2. Dimensions in ( ) are millimeters. 3. Roof curb: 18 gage steel. 4. The 028 and 030 units overhang the roof curbs on supply air/return air end. DIMENSIONS (degrees and inches) UNIT 50DJ,DK B Deg 1.00 C in. 3.25 Deg .50 D in. .75 Fig.
UNIT LEVELING TOLERANCES NOTE: To prevent the hazard of stagnant water build-up in the drain pan of the indoor-air section, unit can only be pitched as shown. NOTES: 1. Roof curb accessory 50DJ900401 is shipped unassembled. 2. Dimensions in ( ) are millimeters. 3. Roof curb: 18 gage steel. 4. The 028 and 030 units overhang the roof curbs on the return air end. DIMENSIONS (degrees and inches) UNIT 50DW,DY B Deg 1.38 C in. 4.00 Fig. 2B — Accessory Roof Curb Dimensions, 50DW,DY 7 Deg .50 D in. .
2. Remove the drain assembly and attach it to the bottom of the unit base rail at the preferred drain location using 4 of the screws provided. See Fig. 5. NOTE: Use a trap at least 4-in. deep. 3. Cover the remaining drain hole with the 16-gage metal seal plate and attach the plate using the other 4 screws provided. See Fig. 6. 4. Apply a bead of RTV or similar sealant around the drain assembly and 16-gage metal seal plate where they attach to the rail. See Fig. 7.
LEGEND CONN — DIM — Connection Dimension NOTES: 1. Dimensions in [ 2. ] are in millimeters. Center of gravity. 3. Allow 128-09 (3658) at top and 68-09 (1829) on sides for service and operational clearance. 4. On multiunit applications allow 128-09 (3658) between adjacent condensers and economizers. 5. For smaller service and operational clearances, contact your local representative. 6. Bottom ducts designed to be attached to accessory roof curb.
LEGEND CONN — Connection DIM — Dimension NOTES: 1. Dimensions in [ 2. UNIT 50DW,DY 024 028 030 ] are in millimeters. Center of gravity. 3. Allow 128-09 (3658) at top and 68-09 (1829) on sides for service and operational clearance. 4. On multiunit applications allow 128-09 (3658) between adjacent condensers and economizers. 5. For smaller service and operational clearances, contact your local representative. 6. Always line up condenser end of unit tight against the roof curb. 7.
Fig. 4 — Drain Location Selection ROOF MOUNT DRAIN Fig. 5 — Condensate Drain Location SLAB MOUNT DRAIN Fig. 7 — Condensate Drain Piping Details Fig. 6 — Seal Plate Location Fig.
Install Outdoor-Air Hoods 25% OUTDOOR-AIR HOOD — This hood is shipped separately from the base unit, in a carton marked 50DJ900411. This carton contains: 1 — hood top 1 — hood side, left 1 — hood side, right 1 — fastener package The fastener package contains: 8 — screws, 1⁄4-in. x 5⁄8-in. long 1 — 1⁄8-in. thick x 1⁄2-in. wide x 6-ft long seal strip with pressure-sensitive adhesive on one side See Fig. 12 and remove 10 of the screws holding the 25% outdoor-air damper assembly to the unit.
5. If unit is not to be equipped with barometric relief or power exhaust, discard the channel clip. If unit is to be equipped with barometric relief or power exhaust, discard one of the channel panels. 6. Cut 2 pieces of seal strip 433⁄4 in. long for placement on the channel panels (or one channel panel and one channel clip if barometric relief or power exhaust is used) on the flanges with the holes. Begin 1 in. from the top of the flange and center the seal strip on the flange, covering the holes.
economizer hood assembly.) Once economizer hood assembly is in place, secure it using 10 of the screws from the fastener package (5 per side). 10. Using 2 of the screws from the fastener package, attach the top flange of the economizer hood assembly to the unit top rail. The holes in the top rail are behind the top rail gasket. 11. Using 4 screws from the fastener package, attach top and bottom of the channel panels and/or clips to the top rail and the base rail.
Cartons contain: 1 — preassembled hood/damper/motor assembly 1 — fastener package (taped to inside of hood) The fastener package contains: 6 — screws, 1⁄4 AB x 5⁄8-in. long 2 — seal strips, 36-in. long x 1-in. wide x 1⁄8-in. thick, with pressure-sensitive adhesive on one side 2 — seal strips, 33-in. long x 1-in. wide x 1⁄8-in. thick, with pressure-sensitive adhesive on one side To install hood: 1. Remove the lagscrews holding the hood assembly to the shipping skid. See Fig. 15. 2.
LEGEND DPS — Differential Pressure Switch IGV — Inlet Guide Vanes OA — Outdoor Air Fig. 16 — Tubing Connection Diagram % Voltage Imbalance max voltage deviation from average voltage = 100 x average voltage EXAMPLE: Supply voltage is 460-3-60. AB =452 v BC =464 v AC =455 v 452 + 464 + 455 Average Voltage = 3 1371 = 3 = 457 Determine maximum deviation from average voltage: (AB) 457 − 452 = 5 v (BC) 464 − 457 = 7 v (AC) 457 − 455 = 2 v Maximum deviation is 7 v.
24-V Connections: 1. Firestat or smoke detector (field-supplied switch 1) — Remove factory-installed jumper wire and wire a fieldsupplied firestat or smoke detector between terminals 2 and 3 on terminal block 2 in the unit control box (see Fig. 18 for the location of terminal block 2 in the control box). 2.
Table 2 — Electrical Data — 50DJ,DW024 NOMINAL V-PH-HZ 208/230-3-60 460-3-60 575-3-60 VOLTAGE RANGE Min 187 414 518 Max 254 508 632 COMPR NO. 1 RLA 43.3 22.1 17.9 LRA 228 114 91 COMPR NO. 2 RLA 31.5 15.7 12.6 LRA 160 80 64 OFM Total FLA POWER EXHAUST FAN MOTOR* IFM Hp FLA 5.0† 15.2 7.5† 22.0 5.0** 12.4 7.5** 19.6 5.0† 7.2 7.5† 10.5 5.0** 6.2 7.5** 9.8 5.0† 5.6 7.5† 8.6 6.4 3.2 4.8 ELECTRIC HEAT POWER SUPPLY FLA kW FLA MCA — 6.6/6.0 — 6.6/6.0 — 6.
Table 3 — Electrical Data — 50DJ,DW028 NOMINAL V-PH-HZ 208/230-3-60 460-3-60 575-3-60 FLA Hp IFM LRA — — — — VOLTAGE RANGE Min 187 414 518 Max 254 508 632 COMPR NO. 1 RLA LRA 63.6 28.6 22.9 Full Load Amps Nominal Horsepower Evaporator (Indoor) Fan Motor Locked Rotor Amps 266 120 96 COMPR NO. 2 RLA 39.7 LRA 198 19.9 99 15.9 MCA MOCP OFM RLA 79 — — — — OFM Total FLA POWER EXHAUST FAN MOTOR* IFM Hp FLA 7.5† 22.0 10.0† 26.4 7.5** 19.6 10.0** 24.2 7.5† 10.5 10.
Table 4 — Electrical Data — 50DJ,DW030 NOMINAL V-PH-HZ 208/230-3-60 460-3-60 575-3-60 FLA Hp IFM LRA — — — — VOLTAGE RANGE Min 187 414 518 Max 254 508 632 COMPR NO. 1 RLA 63.6 30.0 LRA 266 120 22.9 Full Load Amps Nominal Horsepower Evaporator (Indoor) Fan Motor Locked Rotor Amps 96 COMPR NO. 2 RLA 44.3 22.1 LRA 228 114 17.9 MCA MOCP OFM RLA 91 — — — — OFM Total FLA POWER EXHAUST FAN MOTOR* IFM Hp FLA 10.0† 26.4 15.0† 42.0 10.0** 24.2 15.0** 36.6 10.0† 12.5 15.
Table 5 — Electrical Data — 50DK,DY024 NOMINAL V-PH-HZ 208/230-3-60 460-3-60 575-3-60 FLA Hp IFM LRA — — — — VOLTAGE RANGE Min 187 414 518 Max 254 508 632 COMPR NO. 1 RLA 43.3 22.1 17.9 Full Load Amps Nominal Horsepower Evaporator (Indoor) Fan Motor Locked Rotor Amps COMPR NO. 2 LRA 228 114 91 RLA 31.5 15.7 12.6 MCA MOCP OFM RLA — — — — LRA 160 80 64 OFM Total FLA POWER EXHAUST FAN MOTOR* IFM Hp FLA 5.0† 15.2 7.5† 22.0 5.0** 124 7.5** 19.6 5.0† 7.2 7.5† 10.
Table 6 — Electrical Data — 50DK,DY028 NOMINAL V-PH-HZ 208/230-3-60 460-3-60 575-3-60 FLA Hp IFM LRA — — — — VOLTAGE RANGE Min 187 414 518 Max 254 508 632 COMPR NO. 1 RLA 63.6 28.6 22.9 Full Load Amps Nominal Horsepower Evaporator (Indoor) Fan Motor Locked Rotor Amps COMPR NO. 2 LRA 266 120 96 RLA 39.7 19.9 15.9 MCA MOCP OFM RLA — — — — LRA 198 99 79 OFM Total FLA POWER EXHAUST FAN MOTOR* IFM Hp FLA 7.5† 22.0 10.0† 26.4 7.5** 19.6 10.0** 24.2 7.5† 10.5 10.
Table 7 — Electrical Data — 50DK,DY030 NOMINAL V-PH-HZ 208/230-3-60 460-3-60 575-3-60 FLA Hp IFM LRA — — — — VOLTAGE RANGE Min 187 414 518 Max 254 508 632 COMPR NO. 1 RLA 63.6 30.0 22.9 Full Load Amps Nominal Horsepower Evaporator (Indoor) Fan Motor Locked Rotor Amps COMPR NO. 2 LRA 266 120 96 RLA 44.3 22.1 17.9 MCA MOCP OFM RLA — — — — LRA 228 114 91 OFM Total FLA POWER EXHAUST FAN MOTOR* IFM Hp FLA 10.0† 26.4 15.0† 42.0 10.0** 24.2 15.0** 36.6 10.0† 12.5 15.
LEGEND C CB CCB CV DU ECON EQUIP — — — — — — — Compressor Contactor Circuit Breaker Control Circuit Breaker Constant Volume Dummy Terminal Economizer Equipment GND — Ground HR — Heat Relay IFC — Evaporator (Indoor) Fan Motor Contactor IFCB — Evaporator (Indoor) Fan Motor Circuit Breaker NEC — National Electrical Code OFC — Condenser (Outdoor) Fan Motor Contactor P — Terminal Strip PEC — Power Exhaust Contactor PI — Plug TB — Terminal Block TRAN — Transformer Fig.
Fig. 19 — Field Control Thermostat Wiring, 50DJ,DW CV Units Switch 1 — Firestat or smoke detector — normally closed. Switch 2 — Building pressurization switch (energize evaporator-fan motor) — normally open. Switch 3 — Switch to isolate evaporator-fan motor from power exhaust motor — normally closed. Switch 4 — Smoke purge switch (energize power exhaust motor) — normally open. Switch 5 — Switch to provide 24 v to economizer motor — normally open.
4. Switch to drive inlet guide vanes fully open during building pressurization (field-supplied switch 9) — Wire fieldsupplied switch between terminal C on the inlet guide vane differential pressure switch and the normally-closed terminal on the inlet guide vane differential pressure switch. 5.
C CB CCB CH CO COMP CR CS DPS DU EC ECON ECR EFM EQUIP GND HIR HPT HPS HT HTR HV IFC — — — — — — — — — — — — — — — — — — — — — — — IFCB — IFM — IGV IP LPS LS MAT MGV MTR OFC — — — — — — — — OFM — OMR P PEC PL POT RES RS SC SEN SW T TB TRAN U V VAV — — — — — — — — — — — — — — — — LEGEND Contactor, Compressor Circuit Breaker Control Circuit Breaker Crankcase Heater Convenience Outlet Compressor Motor Control Relay Centrifugal Switch Differential Pressure Switch Dummy Terminal Enthalpy Control Econ
LEGEND HIR — Heating Interlock Relay SW — Switch NOTES: 1. SW1 — Field-supplied switch (or timeclock) used to move unit in and out of the occupied mode. 2. If unit has heat, field must wire between terminals 8 and 9 or 8 and 15 and supply power source to drive room terminals wide open during heating. 3. Nite T’Stat — Field-supplied thermostat which can be used to keep building from becoming too hot or too cold when unit is in the unoccupied mode. 4.
DPS ECR HIR IFC MIR MPE NC NO OMR PEC TB — — — — — — — — — — — LEGEND Differential Pressure Switch Economizer Relay Heating Interlock Relay Evaporator (Indoor) Fan Contactor Modulating Interlock Relay Modulating Power Exhaust Normally Closed Normally Open Occupied Mode Relay Power Exhaust Contactor Coil Terminal Block BUILDING PRESSURIZATION Switch 2 Switch 3 Switch 6 Switch 7 Switch 8 Switch 9 Switch 11 Switch 11A SMOKE PURGE Switch 2 Switch 4 Switch 6 Switch 7 Switch 8 Switch 10 Switch 11 Switch 11A S
LEGEND INT — Input RTN — Return Fig. 25 — Two-Step Demand Limit Module NOTES: 1. Demand limit switches are field supplied and wired. 2. Demand limit control module terminal blocks will accept up to 12gage wire. 3. is field wiring. TB — Terminal Block NOTES: 1. Convenience outlet is field supplied. Ground fault outlet should be used. 2. is field wiring. Fig. 26 — 115-V Field Wiring to Accessory 2-Step Demand Limit Control Module Fig.
Check rotation of wheel with arrow on the fan housing. Check fan speed with a strobe-type tachometer, or use this formula: Fan motor rpm x motor sheave pitch diameter (in.) rpm = fan sheave pitch diameter (in.) See Carrier Standard Service Techniques, Refrigerants section, for procedures to add or remove oil. If oil charge is above sight glass, do not remove any oil until the compressor crankcase heater has been on for at least 24 hours.
Table 9A — Evaporator-Fan Pulley Data — Constant Volume Units (50DJ,DW) and Standard VAV Units (50DK,DY) UNIT 50 JD,DK024 DW,DY024 DJ,DK028 DW,DY028 DJ,DK030 DW,DY030 FAN RPM 780* 875 900 980 1090 1160 780* 875 900 980 1090 1160 680† 825 900* 980 1090 1160 680† 825 900* 980 1090 1160 680† 825 900 980* 1090 1160 680† 825 900 980* 1090 1160 MOTOR PULLEY No. Grooves — Type — in. 2 — 3V — 4.75 2 — 3V — 5.30 2 — 3V — 4.12 2 — 3V — 4.50 3 — 3V — 5.00 3 — 3V — 5.30 2 — 3V — 4.75 2 — 3V — 5.30 2 — 3V — 4.
Table 9B — Evaporator-Fan Pulley Data — VAV Units with Inlet Guide Vane and Static Pressure Control Option UNIT 50 DK024 DY024 DK028 DY028 DK030 DY030 FAN RPM 680 785* 875 900 985 990 1075 1095 1160 680 785* 875 900 985 990 1075 1095 1160 680 785 875 900* 985 990 1075 1095 1160 680 785 875 900* 985 990 1075 1095 1160 680 785 875 900 985* 990 1075 1095 1160 680 785 875 900 985* 990 1075 1095 1160 MOTOR PULLEY No. Grooves — Type — in. 2 — 3V — 4.12 2 — 3V — 4.75 2 — 3V — 5.30 2 — 3V — 4.12 2 — 3V — 4.
Table 11 — Fan Performance — 50DJ Units and 50DK Units Without Inlet Guide Vanes UNIT 50DJ,DK AIRFLOW (Cfm) 024 6,000 7,000 8,000 9,000 10,000 UNIT 50DJ,DK AIRFLOW (Cfm) 024 (cont) 6,000 7,000 8,000 9,000 10,000 UNIT 50DJ,DK AIRFLOW (Cfm) 028,030 7,000 8,000 9,000 10,000 11,000 12,000 12,500 UNIT 50DJ,DK AIRFLOW (Cfm) 028,030 (cont) 7,000 8,000 9,000 10,000 11,000 12,000 12,500 0.2 Rpm Bhp 570 1.8 630 2.7 690 3.8 760 5.2 830 6.7 0.4 Rpm Bhp 620 2.2 670 2.9 730 4.2 800 5.4 860 7.2 0.
Table 12 — Fan Performance — 50DW Units and 50DY Units Without Inlet Guide Vanes UNIT 50DW,DY AIRFLOW (Cfm) 024 6,000 7,000 8,000 9,000 10,000 UNIT 50DW,DY AIRFLOW (Cfm) 024 (cont) 6,000 7,000 8,000 9,000 10,000 UNIT 50DW,DY AIRFLOW (Cfm) 028,030 7,000 8,000 9,000 10,000 11,000 12,000 12,500 UNIT 50DW,DY AIRFLOW (Cfm) 028,030 (cont) 7,000 8,000 9,000 10,000 11,000 12,000 12,500 0.2 Rpm Bhp 570 1.9 650 2.9 720 4.1 800 5.4 870 7.2 0.4 Rpm Bhp 620 2.1 690 3.1 760 4.4 830 5.8 900 7.7 2.
Table 13 — Fan Performance — 50DK Units with Inlet Guide Vanes (cont) UNIT 50DK AIRFLOW (Cfm) 028,030 7,000 8,000 9,000 10,000 11,000 12,000 12,500 UNIT 50DK AIRFLOW (Cfm) 028,030 (cont) 7,000 8,000 9,000 10,000 11,000 12,000 12,500 0.2 Rpm Bhp 630 3.2 690 4.3 750 5.7 830 7.3 900 9.7 960 12.1 990 13.4 0.4 Rpm Bhp 660 3.4 730 4.7 790 6.0 860 7.8 930 10.2 990 12.7 1020 13.9 2.2 Rpm Bhp 990 6.9 1040 8.6 1070 10.0 1130 12.3 1170 14.8 — — — — 0.6 Rpm Bhp 700 3.6 770 5.0 830 6.4 890 8.3 960 10.
Table 15 — Component Pressure Drops (in. wg) COMPONENT ECONOMIZER All Units LOW ELECTRIC HEAT 208/230 and 460 V 50DJ,DK 50DW,DY MED ELECTRIC HEAT 208/230, 460 and 575 V 50DJ,DK 50DW,DY HIGH ELECTRIC HEAT 208/230 V 50DJ 50DW 460 and 575 V 50DJ 50DW024 50DW028,030 6000 7000 8000 CFM 9000 10,000 0.18 0.20 0.25 0.28 0.03 0.03 0.11 0.10 0.15 0.14 0.20 0.09 0.24 0.13 0.28 0.12 0.26 0.11 0.11 11,000 12,000 0.32 0.36 0.40 0.16 0.14 0.18 0.15 0.18 0.17 0.19 0.20 0.29 0.14 0.35 0.16 0.41 0.
Table 16 — Configuration Header Jumper Description TXV VAV M m — — — — JUMPER NO. 1,2 FUNCTION Unit Type 3,4,5 No. of Compressors 6 Expansion Valve 7 Power Frequency 8 Not Used SETTING M m m M M M m M m m M m M m m LEGEND Thermostatic Expansion Valve Variable Air Volume Broken jumper (open circuit) Unbroken jumper (closed circuit) Fig.
P1 LEAVING AIR SET POINT POTENTIOMETER TWO-DIGIT DISPLAY P6 (Warm-Up Potentiometer) — Used only if warm-up heat is used (units with optional electric heat). Dip switch 4 must be in ON position. The valid range is 0° F to 95 F. The control has been programmed to use a range of 40 F to 80 F. If the set point is between 0° F and 40 F, control will use a value of 40 F and no error will be indicated. If set point is between 80 F and 95 F, control will use a value of 80 F and again no error will be indicated.
that they are functional, connected properly, and set within proper range for unit configuration. Nominal resistance values for all sensors range from 363,000 to 219 ohms in accordance with Table 20. Normal display code for good sensors and potentiometers is 1. A display code of 0 indicates a faulty potentiometer, thermistor or wiring. A 0 display also indicates that option is not being used. Table 18 shows thermistor and set point potentiometer functions and quick test display codes. 3. Quick Test Steps 2.
Table 18 — Quick Test, Thermistor and Potentiometer Check QUICK TEST STEP NO. NORMAL DISPLAY 1.4 1 1 — Thermistor OK 0 — Thermistor Faulty Leaving Air Thermistor (T1) 1.5 1 1 — Thermistor OK 0 — Thermistor Faulty Entering Air Thermistor (T2) 1.6 1 1 — Resistor OK 0 — Resistor Faulty Circuit 1 Condenser Resistor (T3)* 1.7 1 1 — Resistor OK 0 — Resistor Faulty Circuit 2 Condenser Resistor (T4)* 1.
Table 20 — Sensor Resistance Values TEMP (F) −60 −55 −50 −45 −40 −35 −30 −25 −20 −15 −10 −5 0 5 10 15 20 25 30 35 40 RESISTANCE (Ohms) 362,640 297,140 245,245 202,841 168,250 139,960 116,820 98,420 82,665 69,685 58,915 50,284 42,765 36,475 31,216 26,786 23,164 19,978 17,276 14,980 13,085 TEMP (F) 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 RESISTANCE (Ohms) 11,396 9,950 8,709 7,642 6,749 5,944 5,249 4,644 4,134 3,671 3,265 2,913 2,600 2,336 2,092 1,879 1,689 1,527 1,377 1,244
The microprocessor determines how rapidly capacity steps are added or subtracted based on deviation from leaving-air set point and rate of change of leaving-air temperature. If enthalpy is such that economizer cannot be used for cooling, dampers will go to their minimum position as set by potentiometer P5 (located on accessory reset board). The control will then use mechanical cooling to meet the cooling load.
With smoke purge mode, it is necessary to interrupt power to unit control circuit as described above for building pressurization. All switches and wiring for putting unit into smoke purge mode must be field supplied and installed. Terminals have been provided in unit control box to facilitate field hookups. The field-installed switches must energize return-air fan, drive economizer dampers wide open and, on VAV units, drive return-air fan inlet guide vanes wide open.
HEATER BOX Models 50DJ,DK — Access to the heater box on these units is through the last door on the left side of the unit (when facing condenser coil). Door is marked FAN SECTION. Box is mounted directly under evaporator fan. Models 50DW,DY — Access to the heater box on these units is through the door marked HEAT SECTION. All Units — Heater box contains: • heater limit switches LS1, LS2, etc. • heater elements HTR1, HTR2, etc. NOTE: Only the heater element connectors are located in the heater box.
Fig. 34 — Location of Differential Pressure Switch and Inlet Guide Vane Motor (50DK Units) Fig. 36 — Location of Modulating Power Exhaust Control Box — VAV Units the access door labeled FAN SECTION; this door is right next to the access door to the main unit control box. See Fig. 34. On the 50DY units, the inlet guide vane motor differential pressure switch is located on the post on the left-hand side of the blower assembly (when facing the blower assembly).
FAN SHAFT BEARINGS — Lubricate fan shaft bearings at least once a year with suitable bearing grease. Typical lubricants are given below: Manufacturer Texaco Sunoco Texaco Mobil Lubricant Regal AFB-2* Prestige 42 Multifak 2 Mobilplex EP No. 1 *Preferred lubricant because it contains rust and oxidation inhibitors. On 024 and 030 units, the fan shaft roller bearing (drive end bearing) should be relubricated after the first 600 hours of operation.
AUXILIARY SWITCH, POWER EXHAUST — All constant volume units have an auxiliary switch located on the economizer damper motor. Switch is factory set to prevent the power exhaust from operating when the economizer is less than 50% open. If other than factory setting is desired, adjust as follows: Do not turn motor shaft by hand or with wrench. Damage to the gear train will result. 1. Remove top cover from motor to gain access to motor terminals and cam adjustments. 2. Disconnect controller from motor.
null span, turn null adjusting screw (Fig. 41) clockwise to decrease span and counterclockwise to increase span. All switches leave factory with null span set at maximum position. The smaller the null span, the closer the pressure will be maintained to desired set point. DIFFERENTIAL PRESSURE SWITCH SET POINT AND NULL SPAN (VAV Units Only When Equipped with Modulating Power Exhaust Option) — See Fig. 36. The set point range for this switch is −0.5 in. wg to 10.5 in. wg. Factory setting is 10.1 in. wg.
Fig. 42 — Charging Chart; 50DJ,DK,DW,DY024; System 1 Fig. 45 — Charging Chart; 50DJ,DK,DW,DY028; System 2 Fig. 43 — Charging Chart; 50DJ,DK,DW,DY024; System 2 Fig. 46 — Charging Chart; 50DJ,DK,DW,DY030; System 1 Fig. 44 — Charging Chart; 50DJ,DK,DW,DY028; System 1 Fig.
EVAPORATOR-FAN MOTOR PROTECTION — A manual reset, calibrated trip, magnetic circuit breaker protects against overcurrent. Do not bypass connections or increase the size of the breaker to correct trouble. Determine the cause and correct it before resetting the breaker. CONDENSER-FAN MOTOR PROTECTION — Each condenser-fan motor is internally protected against overtemperature. They are also protected against a severe overcurrent condition by manual reset, calibrated trip magnetic circuit breakers.
Table 23 — Economizer Control Board Checkout, Test 1 Table 21 — Pressure Switch Settings (psig) SWITCH High Low CUTOUT 426 6 7 27 6 4 CUT-IN 320 6 20 67 6 7 MOTOR TEST Control Circuit, 24 V — This control circuit is protected against overcurrent by a 3.2-amp circuit breaker. Breaker can be reset. If it trips, determine cause of trouble before resetting. A Turn minimum position potentiometer fully counterclockwise. B Turn minimum position potentiometer fully clockwise.
Table 25 — Economizer Control Board Checkout, Test 3 MOTOR TEST PROCEDURE A Turn mixed-air potentiometer to the midpoint position. B C Turn mixed-air potentiometer fully counterclockwise. Turn mixed-air potentiometer fully clockwise. BASIC CHECK — Refer to Fig. 50 for control board component identification. EXPECTED RESULT AND RESPONSE Motor should drive to midstroke with the set point set between 60 and 70 F. If not, the control board is faulty.
LEGEND C MAT PL RA STAT — — — — — Contactor Mixed-Air Thermistor Plug Return-Air Thermostat NOTES: 1. Relay contacts 1K and 2K are shown in high enthalpy position. Actuator is controlled by minimum position potentiometer. 2. When electronic switch is energized, MAT controls actuator operation. Fig.
Fig. 50 — Control Board Component Arrangement 3. Reconnect the wires removed in Step 1 above. 4. With the unit power still off, disconnect plug P1 from control board. Install a jumper wire across Pin R and Pin Y1 at plug P1 on the control board. 5. Connect a voltmeter across the coil for compressor no. 1 contactor. 6. Energize unit and monitor the voltage for a few seconds. 4. Turn unit power off and disconnect plug P4 from the control board. 5.
4. Turn unit power off. Disconnect plug P1 from the control board and install jumper wire across Pins R and Y2 at plug P1. 5. Connect a voltmeter across the coil for compressor no. 2 contactor. 6. Energize unit and monitor the voltage for a few seconds. b. Connect the multimeter to read voltage between Pin X at plug P1 and ground. c. Turn unit power on and check the multimeter. Within a few seconds the meter should indicate 24 v. If it does not, the control board is defective and must be replaced. d.
4. If there is no continuity between these points, the board is defective and must be replaced. NOTE: The control board has no time delay. 5. If there is continuity between these points, the problem is at the connection at plug P4 or external to the control board. 6. Turn unit power off. Reconnect plugs P1 and P4. ECONOMIZER BOARD CONTINUITY CHECK — The economizer board is a connection board that is used to interface the economizer circuit with the base unit and thermostat.
The microprocessor has also been programmed to indicate a compressor failure if CR switch is closed when compressor is not supposed to be on. If a failure occurs, the following are possible causes. High-Pressure Switch Open — The high-pressure switch for each compressor is wired in series with 24-v power that energizes compressor relay. If high-pressure switch opens during operation, CR will stop compressor and this will be detected by microprocessor through the feedback contacts.
CODES 59 AND 60: LOW-PRESSURE SWITCH — These codes are used to indicate a low-pressure switch failure. Since the 50DK,DY024-030 units have low-pressure switches but are not monitored individually by the processor, these codes are not used for the 50DK,DY024-030 units. The terminals on the processor board must be jumpered together on the DK,DY units, or an error code will appear. CODES 63 AND 64: OIL PRESSURE SWITCH — These codes are used to indicate an oil pressure switch failure.
For both, the control uses only 80% of the total potentiometer resistance. If resistance of potentiometer is less than 10% or greater than 90%, alarm light will be energized, a diagnostic code of 85 will be displayed when the display button is pushed, and demand limit will be terminated. If a failure occurs, it is probably due to one of the following: Potentiometer Failure — If a potentiometer is shorted or open, a failure will occur.
J7 TP19 J9 TP18 TP10 TP15 2. Check voltage TP20-TP11. 3. If voltage is greater than 13 vdc, reset power and recheck. 4. If voltage is still incorrect, replace processor board. Step 5 — Check relay board outputs from the processor board. 1. Turn power to OFF position. 2. Connect negative test probe to TP19 (meter still set to dc). 3. Turn switch to ON position and enter quick test mode. 4. Check voltage from TP19 to terminal 14 on pin terminal strip J9. 5. If not 112 vdc, replace processor board. 6.
RELAY BOARD CHECKOUT Step 1 — Low-voltage relay resistance check. 1. Turn switch to OFF position. 2. Remove plug connection from terminal strip J6. 3. Set meter to measure resistance. Connect negative test lead to both terminals 11 and 12 of J6. 4. Turn switch to ON position and go into quick test mode. 5. Place other meter lead on terminals shown in Table 29 and check resistances at each quick test step. Table 29 — Resistance Reading QUICK TEST STEP NO. 1.-2.8. 2.9. 3.0. 3.1. 3.2. 3.3.
SERIAL NO.
