background image

heating air delivery temperature and provides approxi-
mately 350 CFM per ton cooling airflow for good
humidity removal.

(3.) HP-EFF (Factory Selected for 50XZ)— Heat Pump

Efficiency provides same airflow for heating and
cooling modes to increase overall HP efficiency;
approximately 350 CFM per ton.

d. AC/HP CFM ADJUST—SELECT NOMINAL, LOW, OR

HIGH AIRFLOW

The AC/HP CFM Adjust select is factory set to the
High-Hi (NOM for 060) tap. The CFM Adjust selections
NOM/LO will regulate airflow supplied for all operational
modes, except non-heat pump heating modes. HI provides
15 percent airflow over nominal unit size selected and LO
provides 10 percent airflow below nominal unit size
selected. CFM Adjust selection options are provided to
adjust airflow supplied to meet individual installation
needs for such things as noise, comfort, and humidity
removal (See Fig. 20, D as indicated).

e. ON/OFF DELAY—SELECT DESIRED

TIME DELAY PROFILE

Four motor operation delay profiles are provided to cus-
tomize and enhance system operation (See Fig. 20, E as
indicated).
Selection options are:

(1.) The standard 90 sec off delay (Factory Setting) at 100

percent airflow in cooling or heat pump heating mode.

(2.) A 30 sec cooling delay with no airflow, 90 sec off

delay at 100 percent airflow profile is used when it is
desirable to allow system coils time to heat-up/cool-
down in conjunction with the airflow in cooling or
heat pump heating mode.

(3.) A no delay option used for servicing unit or when a

thermostat is utilized to perform delay functions.

(4.) ENH, enhanced selection, provides a 30 sec cooling on

delay with no airflow, plus 150 sec at 70 percent
airflow and no off delay for added comfort.
This will minimize cold blow in heat pump operation
and could enhance system efficiency.

f. CONTINUOUS FAN—SELECT DESIRED FAN SPEED

WHEN THERMOSTAT IS SET ON CONTINUOUS FAN

(1.) LO speed—Factory setting, 50 percent cooling mode

airflow.

(2.) MED speed—Move connector to MED, 65 percent

cooling mode airflow.

(3.) HI speed—Move connector to HI, 100 percent cooling

mode airflow (See Fig. 20, F as indicated).

g. LOW-VOLTAGE CIRCUIT FUSING AND REFER-

ENCE

The low-voltage circuit is fused by a board-mounted
5–amp automotive fuse placed in series with the trans-
former SEC2 and the R circuit. The C circuit of the
transformer is referenced to chassis ground through a
printed circuit run at SEC1 connected to metal standoff
marked with ground symbol.

h. BASIC UNIT CONFIGURATION

The following basic configuration of the indoor motor will
provide ARI rated performance of the System. This BASIC
CONFIGURATION should be used when the rated ARI
performance is required, or if system enhancements such
as super dehumidify are not needed.

(1.) AUX HEAT kW/CFM-Select the heater range for the

size of electric heater installed (skip this step if no
heater is installed).

(2.) AC/HP SIZE-Factory selected to match system size

installed, please verify.

(3.) SYSTEM TYPE-Factory selected HP-EFF (for unit

50XZ).

Fig. 13—Electrical Data Legend

C03014

228

    = 1 v

229

    = 2 v

227

    = 2 v

LEGEND

 

FLA

— Full Load Amps

LRA

— Locked Rotor Amps

MCA      --

  Minimum Circuit Amps

MOCP

 —

Maximum Overcurrent Protection

RLA

— Rated Load Amps

NO TES:
1. In compliance with NEC (National Electrical Code) requirements

for multimotor and combination load equipment (refer to NE C
Articles 430 and 440), the overcurrent protective device for the
unit shall be Power

          Supply   fuse. The CGA (Canadian Gas

Association) units may be

 fuse or circuit break 

er.

2. Minimum wire size is based on 60 C copper wire. I f  other than

60 C wire

is used, or if length exceeds wire length in table,

determine siz e from NEC.

.

3. Unbalanced 3-Phase Supply Voltage

Never operate a motor where a phase imbalance in supply volt-
age is greater than 2%. Use the following formula to determine
the percentage of voltage imbalance.

% Voltage imbalance

max voltage deviation from average voltage

= 100 x

average voltage

EXAMPLE: Supply voltage is 230-3-60.

AB = 228 v
BC = 231 v
AC = 227 v

228 + 231 + 227

Average Voltage =

3

 686

=

3

= 229

Determine maximum deviation from average voltage.

(AB) 229 -
(BC) 231 -
(AC) 229 -

Maximum deviation is 2 v.

Determine percent of voltage imbalance.

2

% Voltage Imbalance = 100 x

229

= 0.8%

This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.

IMPORTANT:  If   the supply voltage phase imbalance is
more than 2%, contact your local electric utility company
immediately.

®

*

Heater capacity (kW) based on heater voltage of 208v & 240v.
If power distibution voltage to unit varies from rated heater  
voltage, heater kW will vary accordingly.

12

Summary of Contents for 50XZ024

Page 1: ...FRIGERANT CHARGE 20 NO CHARGE 20 LOW CHARGE COOLING 20 TO USE COOLING CHARGING CHARTS 20 INDOOR AIRFLOW AND AIRFLOW ADJUST MENTS 20 Defrost Control 20 Quiet Shift 20 Defrost 20 MAINTENANCE 22 Air Filter 23 Indoor Blower and Motor 23 Outdoor Coil Indoor Coil and Condensate Drain Pan 23 Outdoor Fan 24 Electrical Controls and Wiring 24 Refrigerant Circuit 24 Indoor Airflow 24 Metering Devices TXV Acc...

Page 2: ...d units can be converted to downflow vertical discharge configurations for rooftop applications RECEIVING AND INSTALLATION Step 1 Check Equipment IDENTIFY UNIT The unit model number and serial number are stamped on the unit identification plate Check this information against shipping pa pers INSPECT SHIPMENT Inspect for shipping damage while unit is still on shipping pallet If unit appears to be d...

Page 3: ...use and at monthly intervals all rigging brackets and straps should be visually inspected for any damage evidence of wear structural deformation or cracks Particular attention should be paid to excessive wear at hoist hooking points and load support areas Brackets or straps showing any kind of wear in these areas must not be used and should be discarded Fig 2 50XZ024 036 Unit Dimensions UNIT ELECT...

Page 4: ...g holds in the composite unit base 4 Thread lifting bracket strapping around bottom perimeter of unit as follows a Open lever of tension buckle ratchet type b Feed strapping through tension buckle as shown in Fig 8 c Pull strapping through tension buckle unit taut Fig 3 50XZ 042 060 Unit Dimensions UNIT ELECTRICAL CHARACTERISTICS UNIT WEIGHT UNIT HEIGHT IN MM A CENTER OF GRAVITY IN MM lb kg X Y Z ...

Page 5: ...stall a 90 degree turn in the return ductwork between the unit and the conditioned space If a 90 degree elbow cannot be installed then a grille of sufficient strength and density should be installed to prevent objects from falling into the conditioned space Units with electric heaters require 90 degree elbow in supply duct 1 All units should have field supplied filters or accessory filter rack ins...

Page 6: ...also be used when required by code for hurricane or seismic conditions This bracket is available through Micrometl C00076 Gasket around outer edge Insulated deck pan Gasket around duct S A R A HVACunit base Gasketing outer flange Flashing field supplied Roofing mater ial field supplied Cant strip field supplied Provided with roofcurb Roof Duct wo rk field supplied Insulation field supplied Roofcur...

Page 7: ...reductions Abrupt change in duct size adversely affects air performance Step 6 Provide for Condensate Disposal NOTE Ensure that condensate water disposal methods comply with local codes restrictions and practices The 50XZ units dispose of condensate through a 3 4 in NPT female fitting that exits on the compressor end of the unit Condensate water can be drained directly onto the roof in rooftop ins...

Page 8: ...ce with NEC ANSI NFPA latest edition and local electrical codes governing such wiring In Canada all electrical connec tions must be in accordance with CSA standard C22 1 Canadian Electrical Code Part 1 and applicable local codes Refer to unit wiring diagram 2 Use only copper conductor for connections between field supplied electrical disconnect switch and unit DO NOT USE ALUMINUM WIRE 3 Be sure th...

Page 9: ...ee the caution label on the transformer or Fig 19 Transformer is factory wired for 230 v operation If supply voltage is 208 v rewire transformer primary as described in Special Procedures for 208 v Operation section EASY SELECT 50XZ EASY SELECT CONFIGURATION TAPS FOR 50XZ Easy Select taps are used by the installer to configure a system The ECM motor uses the selected taps to modify its operation t...

Page 10: ...airflow also marked is approved For increased comfort select the narrowest kW range matching the heater size for example 0 10 for 10 kW heater This airflow must be greater than the minimum for CFM for electric heater application with the size system installed for safe and continuous operation See Tables 4A 4B 4C 5 6 for airflow delivery and minimum CFM Note that airflow marked is the airflow which...

Page 11: ...53 16 9 83 0 0 9 6 8 3 8 5 0 5 4 7 2 7 5 10 0 11 3 15 0 18 1 20 8 26 30 36 1 41 7 54 2 62 5 28 8 28 8 51 4 54 9 61 3 66 3 74 0 80 9 96 5 107 0 35 35 70 70 80 80 90 90 100 110 208 230 3 60 187 253 12 2 77 0 1 6 6 8 3 8 5 0 7 5 10 0 11 3 15 0 10 4 12 0 20 8 24 1 31 3 36 1 23 7 23 7 36 7 38 7 49 7 53 7 62 7 68 8 30 30 50 50 60 60 70 80 042 208 230 1 60 187 253 22 4 105 0 0 9 6 8 3 8 5 0 5 4 7 2 7 5 1...

Page 12: ...ounted 5 amp automotive fuse placed in series with the trans former SEC2 and the R circuit The C circuit of the transformer is referenced to chassis ground through a printed circuit run at SEC1 connected to metal standoff marked with ground symbol h BASIC UNIT CONFIGURATION The following basic configuration of the indoor motor will provide ARI rated performance of the System This BASIC CONFIGURATI...

Page 13: ...Fig 14 Wiring Schematics 50XZ Single Phase C03005 13 ...

Page 14: ...Fig 15 Wiring Schematics 50XZ Three Phase 1 3 2 14 C03006 ...

Page 15: ...humidifying comfort See Fig 20 22 1 AUX HEAT kW CFM Select the narrowest heater range to match size of electric heater installed skip this step if no heater is installed 2 AC HP Size Factory selected to match system size installed please verify 3 SYSTEM TYPE Select system type HP COMFORT for heat pump system or AC for air conditioner system Fig 16 High and Control Voltage Wiring Connections C01028...

Page 16: ...nd AUX2 terminals are not always energized during blower operations as described above When using an electronic air cleaner with the unit use Airflow Sensor P N KEAAC0101AAA The airflow sensor turns on elec tronic air cleaner when the blower is operating d HUMIDIFIER HUMIDISTAT CONNECTIONS Easy Select Board terminals HUM1 and HUM2 are provided for direct connection to the low voltage control of a ...

Page 17: ...r super dehumidify mode the motor delivers reduced airflow to maximize the humidity removal of the system while minimizing over cooling e ELECTRIC HEATING MODE 1 Thermostat closes circuit R to W W1 or W2 The unit delivers the selected electric heat airflow There are no on or off delays f HEAT PUMP HEATING MODE 1 Thermostat closes circuits R to G and R to Y Y2 The unit delivers selected heat pump h...

Page 18: ...roper drainage d Make sure that on the 060 size only the 2 wire ties fastened to the outdoor coils and reversing valve accumulator have been removed e Make sure that all tools and miscellaneous loose parts have been removed 5 Compressors are internally spring mounted Do not loosen or remove compressor hold down bolts 6 Each unit system has 2 Schrader type ports one low side Schrader fitting locate...

Page 19: ...1 Place room thermostat SYSTEM switch or MODE control in OFF position Observe that blower motor starts when FAN mode is placed in FAN ON position and shuts down within 60 sec 030 060 size or 30 sec 024 size when FAN MODE switch is placed in AUTO position 2 Place system switch or MODE control in HEAT position Set control above room temperature Observe that compressor outdoor fan and indoor blower m...

Page 20: ...lem causing the inaccurate readings is a refrigerant leak refer to Check for Refrigerant Leaks section INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS For heating and cooling operation the recommended airflow is 350 to 450 cfm for each 12 000 Btuh of rated cooling capacity For units with optional electric heat the airflow must not be reduced below the levels stated in Table 2 Tables 4A 4B show both heating...

Page 21: ...OMFORT 720 660 790 745 685 890 850 785 030 COOLING 1010 920 825 1105 1030 930 1255 1160 1050 COOLING DEHUMIDIFY 890 845 795 890 865 825 1010 980 925 HEAT PUMP COMFORT 945 850 765 1020 965 895 1140 1105 995 036 COOLING 1110 1025 970 1235 1175 1115 1400 1355 1280 COOLING DEHUMIDIFY 990 960 910 990 975 940 1125 1110 1085 HEAT PUMP COMFORT 1035 975 910 1160 1080 1020 1305 1275 1220 Heat Pump Efficienc...

Page 22: ...er to the unit before performing any maintenance or service on this unit 2 Use extreme caution when removing panels and parts As with any mechanical equipment personal injury can result from sharp edges 3 Never place anything combustible either on or in contact with the unit Errors made when reconnecting wires may cause improper and dangerous operation Label all wires prior to disconnect ing when ...

Page 23: ...re easily cleaned when dry therefore inspect and clean the coils either before or after each cooling season Remove all obstructions including weeds and shrubs that interfere with the airflow through the condenser coil Straighten bent fins with a fin comb If coated with dirt or lint clean the coils with a vacuum cleaner using the soft brush attachment Be careful not to bend the fins If coated with ...

Page 24: ...evice is a TXV type device Fig 27 Cooling Charging Table Subcooling C03027 psig 5 10 15 20 kPa 3 6 8 11 189 61 56 51 46 1303 13 13 11 8 203 66 61 56 51 1399 13 16 13 10 10 3 5 7 9 8 5 4 9 4 5 2 9 5 8 6 4 7 210 68 63 58 53 1448 13 17 14 11 NA NA NA NA NA 217 70 65 60 55 1496 13 18 15 13 17 6 9 8 16 8 9 3 16 5 9 2 15 4 8 6 14 3 7 9 224 72 67 62 57 1544 13 19 16 14 NA NA NA NA NA 231 74 69 64 59 1593...

Page 25: ...switch 3 Apply ohm meter leads across switch You should have continuity on a good switch NOTE Because these switches are attached to refrigeration system under pressure it is not advisable to remove this device for troubleshooting unless you are reasonably certain that a problem exists If switch must be removed remove and recover all system charge so that pressure gauges read 0 psi Never open syst...

Page 26: ...y risk exposure of compressor oil to the roof take appropriate precautions to protect roofing Proce dures which risk oil leakage include but are not limited to compressor replacement repairing refrigerant leaks replacing refrigerant components such as filter drier pressure switch me tering device coil accumulator or reversing valve Synthetic Roof Precautionary Procedure 1 Cover extended roof worki...

Page 27: ...door coil on the bottom circuit and as close to the coil as possible TROUBLESHOOTING Refer to the Cooling and Heating Troubleshooting Chart Table 7 for troubleshooting information START UP CHECKLIST Fig 30 Defrost Thermostat C99029 FEEDER TUBE STUB TUBE DEFROST THERMOSTAT 27 ...

Page 28: ... side with 520 psig low side retard Use hoses with 750 psig service pressure rating Leak detectors should be designed to detect HFC refrigerant Puron as with other HFCs is only compatible with POE oils Vacuum pumps will not remove moisture from oil Only use factory specified liquid line filter driers with rated working pressures no less than 600 psig Do not install a suction line filter drier in l...

Page 29: ...es 3 Complete wiring and install outdoor temperature sensor according to Installation Instructions 1 Configuration Taps See Installation Instructions for detailed description Option 5 Variable Speed Motors set to ON Option 7 Super Dehumidify set to ON Option 12 Heaters during Defrost setting 2 is suggested for all heaters Option 16 Heat pump systems set to ON for warmer heat below 40 F Option 17 S...

Page 30: ...reversing the 3 phase power leads to the unit Compressor cycles other than normally satisfying thermostat Refrigerant overcharge or undercharge Recover refrigerant evacuate system and recharge to capacities shown on nameplate Defective compressor Replace and determine cause Insufficient line voltage Determine cause and correct Blocked outdoor coil Determine cause and correct Defective run start ca...

Page 31: ...e or low side restricted Remove source of restriction Cool Insufficient coil airflow Increase air quantity Check filter replace if necessary Cool Temperature too low in conditioned area Reset thermostat Cool Outdoor ambient below 40 F Install low ambient kit Filter drier restricted Replace Compressor runs but outdoor fan does not NC normally closed contacts on defrost board open Check condition of...

Page 32: ...____DB ___________WB HEAT PUMP SUPPLY AIR ___________ GAS HEAT SUPPLY AIR ___________ ELECTRIC HEAT SUPPLY AIR ___________ PRESSURES GAS INLET PRESSURE ___________IN WG GAS MANIFOLD PRESSURE ___________IN WG REFRIGERANT SUCTION ___________PSIG SUCTION LINE TEMP ___________ REFRIGERANT DISCHARGE ___________PSIG DISCHARGE TEMP ___________ VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS GAS HEAT TEMP...

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