Air Conditioner User Manual

ManualsBrandsYork ManualsAir CompressorPREDATOR 150

INSTALLATION

MANUAL

CAUTION: READ ALL SAFETY GUIDES BEFORE YOU

BEGIN TO INSTALL YOUR UNIT.

SAVE THIS MANUAL

SINGLE PACKAGE AIR CONDITIONERS AND

SINGLE PACKAGE ELECTRIC UNITS

DM090, 120 and 150

7-1/2 TO 12-1/2 TON

(380V, 3 Phase, 60 HZ)

035-17311-002-A-0803

NOTES, CAUTIONS AND WARNINGS

The installer should pay particular attention to the words:

NOTE, CAUTION, and WARNING. Notes

are intended to

clarify or make the installation easier. Cautions

are given

to prevent equipment damage. Warnings

are given to alert

installer that personal injury and/or equipment damage

may result if installation procedure is not handled properly.

CONTENTS

GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . .5

INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

REFERENCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

APPROVALS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

NOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

START-UP (COOLING). . . . . . . . . . . . . . . . . . . . . . . . . .37

NORMAL MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . .39

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . .39

See following pages for a complete Table of Contents.

Summary of content (44 pages)

PAGE 1
INSTALLATION MANUAL ® SINGLE PACKAGE AIR CONDITIONERS AND CONTENTS GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . .5 INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 REFERENCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 SINGLE PACKAGE ELECTRIC UNITS DM090, 120 and 150 7-1/2 TO 12-1/2 TON (380V, 3 Phase, 60 HZ) APPROVALS. . . . . . . . . . . . . .
PAGE 2
035-17311-002-A-0803 TABLE OF CONTENTS GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 METHOD ONE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 METHOD TWO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . 5 SUPPLY AIR DRIVE ADJUSTMENT . . . . . . . . . . . . . . . . . 32 INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PAGE 3
035-17311-002-A-0803 LIST OF FIGURES Fig. # Pg.# Fig. # Pg.# 1 UNIT SHIPPING BRACKET . . . . . . . . . . . . . . . . . . . . 10 13 SIDE PANELS WITH HOLE PLUGS . . . . . . . . . . . . . 16 2 CONDENSER COVERING . . . . . . . . . . . . . . . . . . . . 10 14 RETURN DOWNFLOW PLENUM WITH PANEL . . . 16 3 COMPRESSOR SECTION . . . . . . . . . . . . . . . . . . . . . 10 15 DISCHARGE PANEL IN PLACE . . . . . . . . . . . . . . . . 16 4 PREDATOR® COMPONENT LOCATION . . . . . . . . .
PAGE 4
035-17311-002-A-0803 LIST OF TABLES Tbl.# Pg.# 1 UNIT VOLTAGE LIMITATIONS . . . . . . . . . . . . . . . . . 11 2 UNIT TEMPERATURE LIMITATIONS . . . . . . . . . . . . 11 3 UNIT WEIGHTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4 6 POINT LOAD WEIGHT . . . . . . . . . . . . . . . . . . . . . . 12 5 4 POINT LOAD WEIGHT . . . . . . . . . . . . . . . . . . . . . . 12 6 UNIT CLEARANCES . . . . . . . . . . . . . . . . . . . . . . . . . 13 7 CONTROL WIRE SIZES . . . . . . . . . . .
PAGE 5
035-17311-002-A-0803 GENERAL REFERENCE YORK Predator® units are single package air conditioners designed for outdoor installation on a rooftop or slab and for non-residential use. These units can be equipped with factory or field installed electric heaters for heating applications.
PAGE 6
035-17311-002-A-0803 NOMENCLATURE 6½ - 12½ Ton Predator Model Number Nomenclature D M 090 C00 A 3 A AA 3 Product Generation Product Category 3 = Third Generation D = Air Cond., Single Package Product Identifier Voltage Installation Options Additional Options M = R-22 Standard Efficiency 3 = 380-3-60 Nominal Cooling Capacity - MBH 090 = 7-½ Ton 120 = 10 Ton 150 = 12-½ Ton Heat Type & Nominal Heat Capacity C00 = Cooling Only.
PAGE 7
035-17311-002-A-0803 NOMENCLATURE, ADDITONAL OPTIONS: AA None AB Phase Monitor AC Coil Guard AD Dirty Filter Switch AE Phase Monitor & Coil Guard AF Phase Monitor & Dirty Filter Switch AG Coil Guard & Dirty Filter Switch AH Phase Monitor, Coil Guard, & Dirty Filter Switch CA CPC Controller with Dirty Filter Switch & Air Proving Switch CB CPC Controller, DFS, APS & Phase Monitor CC CPC Controller, DFS, APS & Coil Guard CD CPC Controller, DFS, APS, Phase Monitor, & Coil Guard CE CPC
PAGE 8
035-17311-002-A-0803 HN Honeywell Excel 10 Controller, DFS, APS & Technicoat Evap. & Cond Coils HP Honeywell Excel 10 Controller, DFS, APS, Technicoat Evap. & Cond Coils, & Phase Monitor HQ Honeywell Excel 10 Controller, DFS, APS, Technicoat Evap. & Cond Coils, & Coil Guard HR Honeywell Excel 10 Controller, DFS, APS, Technicoat Evap.
PAGE 9
035-17311-002-A-0803 TE Technicoat Condenser Coil, Phase Monitor, & Coil Guard TF Technicoat Condenser Coil, Phase Monitor, & Dirty Filter Switch TG Technicoat Condenser Coil, Coil Guard, & Dirty Filter Switch TH Technicoat Condenser Coil, Phase Monitor, Coil Guard, & Dirty Filter Switch TJ Technicoat Evaporator Coil TK Technicoat Evaporator Coil & Phase Monitor TL Technicoat Evaporator Coil & Coil Guard TM Technicoat Evaporator Coil & Dirty Filter Switch TN Technicoat Evaporator Coil, Pha
PAGE 10
035-17311-002-A-0803 INSTALLATION INSTALLATION SAFETY INFORMATION Read these instructions before continuing this appliance installation. This is an outdoor combination heating and cooling unit. The installer must assure that these instructions are made available to the consumer and with instructions to retain them for future reference. 1. Install this furnace only in a location and position as specified on Page 11 of these instructions. 2.
PAGE 11
035-17311-002-A-0803 Terminal block for hi-voltage connection Simplicity™ Control board w/screw connector Disconnect location for T-stat wiring and (optional disconnect switch) network connection Filter access (2” throw-away) Filter drier (solid core) Condenser section Second model nameplate inside hinged access panel Belt-drive blower motor Slideout motor & blower assembly for easy access adjustment & service Dual stage cooling for max.
PAGE 12
035-17311-002-A-0803 TABLE 4: 6 POINT LOAD WEIGHT Location (lbs.)* Model Before lifting, make sure the unit weight is distributed equally on the rigging cables so it will lift evenly. Units may be moved or lifted with a forklift. Slotted openings in the base rails are provided for this purpose. LENGTH OF FORKS MUST BE A MINIMUM OF 60 INCHES. A B C D E F DM090 158 142 128 187 207 230 DM120 168 151 136 198 219 244 DM150 180 161 145 212 235 262 *.
PAGE 13
035-17311-002-A-0803 Do not permit overhanging structures or shrubs to obstruct condenser air discharge outlet, combustion air inlet or vent outlets.
PAGE 14
035-17311-002-A-0803 .
PAGE 15
035-17311-002-A-0803 DUCTWORK DUCT COVERS Ductwork should be designed and sized according to the methods in Manual D of the Air Conditioning Contractors of America (ACCA) or as recommended by any other recognized authority such as ASHRAE or SMACNA. Units are shipped with the side duct openings covered and a covering over the bottom of the unit. For bottom duct application, no duct cover changes are necessary.
PAGE 16
035-17311-002-A-0803 CONDENSATE DRAIN When fastening ductwork to side duct flanges on unit, insert screws through duct flanges only. DO NOT insert screws through casing. Outdoor ductwork must be insulated and water-proofed. The side condensate drain is reversible and maybe re-oriented to the rear of the cabinet to facilitate condensate piping. A condensate drain connection is available through the base pan for piping inside the roof curb. Trap the connection per Figure 16.
PAGE 17
035-17311-002-A-0803 THERMOSTAT WIRING The thermostat should be located on an inside wall approximately 56 inches above the floor where it will not be subject to drafts, sun exposure or heat from electrical fixtures or appliances. Follow the manufacturer's instructions enclosed with thermostat for general installation procedure. Seven (7) color-coded, insulated wires should be used to connect the thermostat to the unit. Refer to Table 7 for control wire sizing and maximum length.
PAGE 18
035-17311-002-A-0803 T H E R M T E R M O S T A T IN A L S 1 U N IT T E R M IN A L S S T R IP T B 1 R C R H R Y 1 Y 1 Y 2 Y 2 W 1 W W 2 1 W G 2 G C C X 1 X 3 2 4 X 2 V o lt T r a n s fo r m e r O C C X 4 A 1 A 2 T T T O R E M O T E S E N S O R 2 E T 0 4 7 0 1 3 2 4 IF U S E D 1 2 E le c tr o n ic p r o g r a m m a b le T h e r m o s ta t 2 E T 0 7 7 0 0 1 0 0 2 4 ( in c lu d e s s u b b a s e ) .
PAGE 19
035-17311-002-A-0803 T E R M IN A L B L O C K T B 1 F A C T O R Y O R F IE L D S U P P L IE D D IS C O N N E C T G R O U N D L U G T H R P H A P O W S U P E E S E E R P L Y FIGURE 19 - FIELD WIRING DISCONNECT TABLE 8: ELECTRICAL DATA - DM090 (7-1/2 TON) WITHOUT POWER CONVENIENCE OUTLET Compressors Voltage RLA ea. 380 * LRA ea. 1.5 HP 2 HP Pwr Pwr Conv Exh Motor Outlet FLA Electric Heater Model No. Actual Heater KW Amps FLA -5.6 11.3 15 21.3 -8.5 17.2 22.8 32.4 Min.
PAGE 20
035-17311-002-A-0803 TABLE 10: ELECTRICAL DATA - DM120 (10 TON) WITHOUT POWER CONVENIENCE OUTLET Pwr Pwr Supply OD Fan Conv Compressors Blower Motor Exh Motors Voltage Motor Outlet FLA RLA ea. 380 * LRA ea. FLA ea. 2 HP 3 HP FLA Electric Heater Model No. FLA None 2TP04521850 0.0 11.5 75.0 1.6 4.1 5.3 2.2 2TP04522450 2TP04523650 2TP04525450 Maximum HACR breaker of the same AMP size is applicable. Max Max Fuse* MCA Min.
PAGE 21
035-17311-002-A-0803 TABLE 14: PHYSICAL DATA Models Component Evaporator Blower Evaporator Coil DM 090 120 150 Blower, Centrifugal (Dia. X Wd. in.) 15 x 15 15 x 15 15 x 15 Motor, Standard (HP) 1-1/2 2 3 Motor, Optional (HP) 2 3 5 Rows 2 2 3 Fins per Inch 15 15 15 Height (in.) 2 Face Area (ft. each) Condenser Fan (2 per Unit) Condenser Coil (2 per unit) DM DM Refrigerant Charge DM Compressors DM Air Filters 40 40 13.2 13.2 Propeller Dia. (in.
PAGE 22
035-17311-002-A-0803 ON position and then OFF or energize and de-energize terminals “R” to “G”. ECONOMIZER The Economizer can be a factory installed option or a field installed accessory. If factory installed, refer to the instructions included with the outdoor air hood to complete the assembly. Field installed Economizer accessories include complete instructions for installation.
PAGE 23
035-17311-002-A-0803 CONTROL CURVE CONTROL POINT APPROX.
PAGE 24
035-17311-002-A-0803 PHASING A Predator® units are properly phased at the factory. Check for proper compressor rotation. If the blower or compressors rotate in the wrong direction at start-up, the electrical connection to the unit is misphased. Change the phasing of the Field Line Connection at the factory or field supplied disconnect to obtain proper rotation. (Scroll compressors operate in only one direction.
PAGE 25
035-17311-002-A-0803 TABLE 17: 7-1/2 TON STANDARD MOTOR DOWN SHOT BLOWER PERFORMANCE* † TURNS OPEN ** ESP‡ 0 1 2 3 4 5 CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP 0.2 - - - 3715 1573 1.69 3634 1434 1.54 3431 1265 1.36 3218 901 0.97 3024 976 1.05 0.4 3650 1657 1.78 3510 1490 1.60 3320 1313 1.41 3079 1145 1.23 2832 810 0.87 2586 860 0.92 0.6 3334 1522 1.63 3146 1351 1.45 2910 1169 1.25 2621 1005 1.
PAGE 26
035-17311-002-A-0803 TABLE 19: 10 TON STANDARD MOTOR DOWN SHOT BLOWER PERFORMANCE* † TURNS OPEN** ESP‡ 0 1 2 3 4 5 CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP 0.2 - - - - - - - - - 3896 1639 1.76 3688 1453 1.56 3447 1268 1.36 0.4 4040 2076 2.23 4005 1934 2.07 3790 1698 1.82 3569 1508 1.62 3333 1330 1.43 3057 1147 1.23 0.6 3890 2006 2.15 3697 1790 1.92 3427 1550 1.66 3152 1356 1.45 - - - - - - 0.
PAGE 27
035-17311-002-A-0803 TABLE 21: 12-1/2 TON STANDARD MOTOR DOWN SHOT BLOWER PERFORMANCE* † TURNS OPEN ** ESP‡ 0 1 2 3 4 5 CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP 0.4 5078 3630 3.89 4809 3103 3.33 4594 3053 3.27 4360 2478 2.66 4090 2093 2.24 3812 1798 1.93 0.6 4865 3456 3.71 4584 2961 3.17 4349 2912 3.12 4106 2318 2.49 3814 1964 2.11 - - - 0.8 4642 3284 3.52 4356 2828 3.03 4089 2776 2.98 3840 2137 2.
PAGE 28
035-17311-002-A-0803 TABLE 23: 7-1/2 TON STANDARD MOTOR SIDE SHOT BLOWER PERFORMANCE* † TURNS OPEN** ESP‡ 0 1 2 3 4 5 CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP 0.4 - - - - - - 3736 1476 1.58 3487 1284 1.38 3231 1109 1.19 3001 970 1.04 0.6 - - - 3572 1514 1.62 3389 1339 1.44 3094 1151 1.23 2764 972 1.04 2446 824 0.88 0.8 3422 1558 1.67 3179 1364 1.46 2889 1164 1.25 2554 985 1.06 - - - - - - 1.
PAGE 29
035-17311-002-A-0803 TABLE 25: 10 TON STANDARD MOTOR DOWN SHOT BLOWER PERFORMANCE* † TURNS OPEN ** ESP‡ 0 1 2 3 4 5 CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP 0.2 - - - - - - - - - 3896 1639 1.76 3688 1453 1.56 3447 1268 1.36 0.4 4040 2076 2.23 4005 1934 2.07 3790 1698 1.82 3569 1508 1.62 3333 1330 1.43 3057 1147 1.23 0.6 3890 2006 2.15 3697 1790 1.92 3427 1550 1.66 3152 1356 1.45 - - - - - - 0.
PAGE 30
035-17311-002-A-0803 TABLE 27: 12-1/2 TON STANDARD MOTOR SIDE SHOT BLOWER PERFORMANCE* † TURNS OPEN ** ESP‡ 0 1 2 3 4 5 CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP CFM W†† BHP 0.4 - - - - - - 5201 3162 3.39 4966 2796 3.00 4681 2405 2.58 4355 2054 2.20 0.6 - - - 5220 3395 3.64 4942 2980 3.20 4657 2608 2.80 4358 2230 2.39 4007 1890 2.03 3194 3.43 4661 2806 3.01 4378 2572 2.76 4016 2057 2.21 0.
PAGE 31
035-17311-002-A-0803 TABLE 29: INDOOR BLOWER SPECIFICATIONS MODEL DM090 DM120 DM150 MOTOR MOTOR SHEAVE BLOWER SHEAVE BELT HP RPM Eff. SF Frame Datum Dia. (in.) Bore (in.) Model Datum Dia. (in.) Bore (in.) Model 1-1/2 1725 80% 1.15 56 3.4 - 4.4 7/8 1VM50 9.0 1 AK94 2 1725 80% 1.15 56 3.4 - 4.4 7/8 1VM50 7.5 1 AK79 A55 2 1725 80% 1.15 56 3.4 - 4.4 7/8 1VM50 8.5 1 AK89 A56 3 1725 80% 1.15 56 3.4 - 4.4 7/8 1VM50 7.0 1 AK74 A54 3 1725 80% 1.
PAGE 32
035-17311-002-A-0803 FIGURE 23 - DRY COIL DELTA P SUPPLY AIR DRIVE ADJUSTMENT EXAMPLE A 12.5 ton unit was selected to deliver 4,000 CFM with a 3 HP motor, but the unit is delivering 3,800 CFM. The variable pitch motor sheave is set at 2 turns open. Before making any blower speed changes review the installation for any installation errors, leaks or undesirable systems effects that can result in loss of airflow.
PAGE 33
035-17311-002-A-0803 TABLE 30: ADDITIONAL STATIC RESISTANCE CFM Cooling Only* Economizer† ‡ Electric Heat KW† 9 18 24 36 54 2300 0.08 0.02 0.07 0.08 0.09 0.10 0.13 2500 0.09 0.02 0.08 0.09 0.10 0.11 0.14 2700 0.11 0.03 0.09 0.10 0.12 0.13 0.16 2900 0.12 0.03 0.10 0.11 0.13 0.14 0.18 3100 0.14 0.03 0.12 0.13 0.15 0.16 0.20 3300 0.16 0.03 0.13 0.14 0.17 0.18 0.22 3500 0.18 0.04 0.15 0.16 0.19 0.20 0.24 3700 0.20 0.04 0.17 0.18 0.21 0.
PAGE 34
035-17311-002-A-0803 COOLING SEQUENCE OF OPERATION CONTINUOUS BLOWER By setting the room thermostat fan switch to "ON," the supply air blower will operate continuously. INTERMITTENT BLOWER With the room thermostat fan switch set to "AUTO" and the system switch set to either the "AUTO" or "HEAT" settings, the blower is energized whenever a cooling or heating operation is requested. The blower is energized after any specified delay associated with the operation.
PAGE 35
035-17311-002-A-0803 COOLING OPERATION ERRORS LOW AMBIENT COOLING Each cooling system is monitored for operation outside of the intended parameters. Errors are handled as described below. All system errors override minimum run times for compressors. To determine when to operate in low ambient mode, the UCB has a pair of terminals connected to a temperature-activated switch set at 45ºF.
PAGE 36
035-17311-002-A-0803 a compressor too soon after its previous run. Additionally, a minimum run time is imposed any time a compressor is energized. The ASCD is initiated on unit start-up and on any compressor reset or lock-out. Limit Setting Table 32. It resets automatically. The limit switch operates when a high temperature condition, caused by inadequate supply air flow occurs, thus shutting down the heater and energizing the blower.
PAGE 37
035-17311-002-A-0803 START-UP (COOLING) OPERATING INSTRUCTIONS 1. PRESTART CHECK LIST NOTE: Prior to each cooling season, the crankcase heaters must be energized at least 10 hours before the system is put into operation. After installation has been completed: 1. Turn unit electrical power on. Check the electrical supply voltage being supplied. Be sure that it is the same as listed on the unit nameplate. 2. Set the room thermostat setting to lower than the room temperature. 3.
PAGE 38
035-17311-002-A-0803 TABLE 35: 10 TON STANDARD EFFICIENCY SUPERHEAT CHARGING Superheat at Compressor Suction (°F) Airflow = 4000 CFM Outdoor Temp (°F) Indoor WB Temp (°F) 55 57 59 61 63 65 67 69 71 73 75 65 19.6 20.8 22.0 23.2 24.4 25.6 26.9 28.4 29.9 31.4 32.9 70 14.4 16.0 17.5 19.0 20.5 22.0 23.5 25.4 27.3 29.2 31.0 75 9.3 11.1 12.9 14.7 16.6 18.4 20.2 22.4 24.7 26.9 29.1 80 - 6.3 8.4 10.5 12.6 14.8 16.9 19.5 22.0 24.6 27.2 85 - - - 6.3 8.
PAGE 39
035-17311-002-A-0803 NORMAL MAINTENANCE Prior to any of the following maintenance procedures, shut off all power to the unit to prevent personal injury. Periodic maintenance normally consists of changing or cleaning filters. GENERAL FILTERS TROUBLESHOOTING Troubleshooting of components may require opening the electrical control box with the power connected to the unit.
PAGE 40
035-17311-002-A-0803 TABLE 37: UNIT CONTROL BOARD FLASH CODES Flash Code Description On Steady Control Failure - Replace Control Heart Beat Normal Operation 1 Flash Not Applicable 2 Flashes Control waiting ASCD* 3 Flashes HPS1 - Compressor Lock out 4 Flashes HPS2 - Compressor Lock out 5 Flashes LPS1 - Compressor Lock out 6 Flashes LPS2 - Compressor Lock out 7 Flashes FS1 - Compressor Lock out 8 Flashes FS2 - Compressor Lock out 9 Flashes Ignition Control Locked Out/ Ignition Control
PAGE 41
035-17311-002-A-0803 COOLING TROUBLESHOOTING GUIDE On calls for cooling, if the compressors are operating but the supply air blower motor does not energize after a short delay (the room thermostat fan switch is in the “AUTO” position): 1. If installed, check the position of the economizer blades. If the blades are open, the economizer is providing free cooling and the compressors will not immediately operate.
PAGE 42
035-17311-002-A-0803 locked out the compressor for repeat trips. The UCB should be flashing an alarm code. If not, press and release the ALARMS button on the UCB. The UCB will flash the last five alarms on the LED. If the compressor is locked out, cancel any call for cooling. This will reset any compressor lock outs. NOTE: While the above step will reset any lockouts, compressor #1 may be held off for the ASCD. See the next step. 10.
PAGE 43
035-17311-002-A-0803 9. If 24 volts is present at the UCB Y2 terminal and none of the protection switches have opened, the UCB may have locked out the compressor for repeat trips. The UCB should be flashing a code. If not, press and release the ALARMS button on the UCB. The UCB will flash the last five alarms on the LED. If the compressor is locked out, 6. If 24 volts is not present at M1, check for 24 volts at the UCB terminal, C1.
PAGE 44
terminal. If 24 volts is not present, check for loose wiring from the Y1 “OUT” terminal to the Mate-N-Lock plug, a poor connection between the UCB and economizer Mate-N-Lock plugs, loose wiring from the Mate-N-Lock plug to the economizer, back to the Mate-N-Lock plug, and from the Mate-N-Lock plug to the Y1 “ECON” terminal. The economizer control may have faulted and is not returning the 24 volts to the Y1 “ECON” terminal even though the economizer is not providing free cooling.