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14

Utilization Voltage - The voltage of the line terminals of the equip-
ment at which the equipment must give fully satisfactory perfor-
mance. Once it is established that supply voltage will be main-
tained within the utilization range under all system conditions,
check and calculate if an unbalanced condition exists between
phases. Calculate percent voltage unbalance as follows:

Three Phase Models

3) PERCENT VOLTAGE 

      UNBALANCE 

2) MAXIMUM VOLTAGE DEVIATIONS

FROM AVERAGE VOLTAGE

1) AVERAGE VOLTAGE

HOW TO USE THE FORMULA:
EXAMPLE: With voltage of 220, 216, and 213
1) Average Voltage = 220+216+213=649 / 3 = 216
2) Maximum Voltage Deviations from Average Voltage = 220 - 216 = 4

3) Percent Voltage Unbalance = 100 x 

  = 

=  1.8% 

Percent voltage unbalance MUST NOT exceed 2%

.

4

216

400
216

= 100 X 

C

ONTROL

 V

OLTAGE

 C

HECK

With disconnect switch in the open “OFF” position, disconnect
blue wire from low voltage transformer TRANS1. Close the discon-
nect switch to energize TRANS1 control transformer. Check pri-
mary and secondary (24V) of control transformer TRANS1.

AIR FLOW ADJUSTMENTS

NOTE: For 2 Speed Models, airflow adjustments must be made on
high speed, i.e., 2nd stage cooling or in heat mode.

The drive on the supply fan is typically set in the middle of the
RPM range. The drive motor sheave pitch diameter is field adjust-
able for the required airflow. Refer to the following “Drive
Adjustments” section.

When the final adjustments are complete, the current draw of the
motor should be checked and compared to the full load current
rating of the motor. The amperage must not exceed the service
factor stamped on the motor nameplate.  The total airflow must
not be less than that required for operation of the electric heaters
or the furnace.

If an economizer is installed, check the unit operating balance with
the economizer at full outside air and at minimum outside air.  Upon
completion of the air flow balancing, we recommend replacing
the variable pitched motor sheave with a properly-sized fixed
sheave. A matching fixed sheave will provide longer belt and bear-
ing life and vibration free operation. Initially, it is best to have a
variable pitched motor sheave for the purpose of airflow balanc-
ing, but once the balance has been achieved, fixed sheaves main-
tain alignment and minimize vibration more effectively. For direct
drive units, move green wire for fan.

NOTE: On “non-two speed models” (two-speed models have a “V”
in the eleventh character of the model number), never run CFM
below 300 CFM per ton. Evaporator freezing or poor unit perfor-
mance is possible.

E

VAPORATOR

 F

AN

 R

OTATION

 C

HECK

Check that fan rotates clockwise when viewed from the drive side
of unit and in accordance with rotation arrow shown on blower
housing. If it does not, reverse any two incoming power cables at
Single Point Power Block. In this case, repeat bearing check.

Do not attempt to change load side wiring. Internal wiring assures
all motors and compressors will rotate in correct direction once
evaporator fan motor rotation check has been made.

E

LECTRICAL

 I

NPUT

 C

HECK

Make preliminary check of evaporator fan ampere draw and verify
that motor nameplate amps are not exceeded. A final check of
amp draw should be made upon completion of air balancing of
the duct system (see Appendix C).

S

ET

 E

VAPORATOR

 F

AN

 R

PM

Actual RPM’s must be set and verified with a tachometer or strobe
light. Refer to Appendices A and B for basic unit fan RPM.  Refer
also to “Airflow” section of this manual. With disconnect switch
open, disconnect thermostat wires from terminals Y and W. This
will prevent heating and mechanical cooling from coming on. Place
a jumper wire across terminals R and G at TB1 terminal block. Close
disconnect switch; evaporator fan motor will operate so RPM can
be checked.

For gas heat units, the airflow must be adjusted so that the air
temperature rise falls within the ranges given stated on Data Plate
(see Appendix A - Blower Performance).

BELT DRIVE MODELS ONLY

The drive on the supply fan is typically set in the middle of the
RPM range. The drive motor sheave pitch diameter is field adjust-
able for the required airflow. Refer to “Motor Sheave Adjustmens”
section.

Upon completion of the air flow balancing, we recommend re-
placing the variable pitched motor sheave with a properly-sized
fixed sheave. A matching fixed sheave will provide longer belt and
bearing life and vibration free operation. Initially, it is best to have
a variable pitched motor sheave for the purpose of airflow balanc-
ing, but once the balance has been achieved, fixed sheaves main-
tain alignment and minimize vibration more effectively. For direct
drive units, move fan speed wire.

B

EARING

 C

HECK

Prior to energizing any fans, check and make sure that all setscrews
are tight so that bearings are properly secured to shafts.

T

ENSION

 

AND

 A

LIGNMENT

 A

DJUSTMENT

Correct belt tension is very important to the life of your belt. Too
loose a belt will shorten its life; too tight, premature motor and
bearing failure will occur. Check you belt drive for adequate “run-
in” belt tension by measuring the force required to deflect the
belt at the midpoint of the span length. Belt tension force can be
measured using a belt tension gauge, available through most belt
drive manufacturers.

Summary of Contents for DCG Series

Page 1: ...Installation and Maintenance Manual IM 1213 Group Applied Air Systems Part Number IM 1213 Date January 2014 Light Commercial Packaged Gas Units DCG Series 15 20 Tons...

Page 2: ...ngle package heating and cooling units See the Specification Sheet applicable to your model for information regarding accessories NOTE Please contact your distributor or our website for the applicable...

Page 3: ...11 Circulating Air and Filters 12 Venting 12 Condensate Drain Connection 12 Startup Adjustments and Checks 13 Air flow Adjustments 14 Motor Sheave Adjustments 15 Gas System Check 15 Normal Sequence O...

Page 4: ...S SCREWS CLIPS AND SIMILAR ITEMS INHERENTLY HAVE SHARP EDGES AND IT IS NECESSARY THAT THE INSTALLER AND SERVICE PERSONNEL EXERCISE CAUTION CAUTION DO NOT CONNECT TO OR USE ANY DEVICE THAT IS NOT DESIG...

Page 5: ...ity to install the product in accordance with National Codes and or prevailing local codes and regulations The heating and cooling capacities of the unit should be greater than or equal to the design...

Page 6: ...ine Common sources of such compounds include swimming pool chemicals and chlorine bleaches paint stripper adhesives paints varnishes sealers waxes which are not yet dried and solvents used during cons...

Page 7: ...to protect the unit from damage while lifting with forks The shipping brace is located under the unit under compressor Also remove the fork hole brackets as shown in the following figure 2 Locate and...

Page 8: ...r unit operation A total clearance of75 aroundthisunitisrecommendedto facilitatepossibleblower assembly shaft wheel replacement coil heat exchanger electric heat and gas furnace removal This unit must...

Page 9: ...Installation Instructions Refer to the Roof Curb Installation Instructions for proper curb installation Curbing must be installed in compliance with the Na tional Roofing Contractors Association Manu...

Page 10: ...data plate NOTE If supply voltage is 208V all leads on primary of transformer TRANS1 must be moved from the 230V to the 208V tap Main power wiring should be sized for the minimum wire ampacity shown...

Page 11: ...ing runs not exceeding 75feet Use 16 AWG wire for 24V control wiring runs not exceeding 125 feet Use 14 AWG wire for 24V control wiring runs not exceeding 200 feet Low voltage wiring may be National E...

Page 12: ...ting Value of Gas BTU Cubic Foot CFH BTUH Furnace Input Refer to the Proper Piping Practice drawing for the general layout at the unit The following rules apply 1 Use black iron pipe and fittings for...

Page 13: ...DEVICE WARNING IMPORTANT NOTE Propane gas conversion kits must be installed to convert units to propane gas All propane gas equipment must conform to the safety standards of the National Board of Fir...

Page 14: ...ering side of the gas valve for test gauge connection to measure supply main gas pressure Another 1 8 tap is provided on the side of the manifold for checking manifold pressure THIS UNIT AND ITS INDIV...

Page 15: ...oils fans and motors for unacceptable levels of construction dust and dirt and install new filters CONTRACTOR RESPONSIBILITY The installing contractor must be certain that All supply and return air du...

Page 16: ...unit perfor mance is possible EVAPORATOR FAN ROTATION CHECK Check that fan rotates clockwise when viewed from the drive side of unit and in accordance with rotation arrow shown on blower housing If it...

Page 17: ...are in place and the set screws tight before starting drive Recheck set screws and belt tension after 24 hours service NOTE Future adjustments should be made by loosening the belt tension and increasi...

Page 18: ...ane gas Check the location of the ignition electrode and the flame sensor for correct gap setting Flame Sensor Ignitor NATURAL PROPANE LP 350 000 7 50 000 30 48 400 000 8 50 000 30 48 GASORIFICES MAXI...

Page 19: ...put rate by varying the adjustment of the gas pressure regulator on the gas valve All adjustments must be made with furnace operating at high fire and at normal operating tempera ture A manometer shou...

Page 20: ...s a three 3 try spark ignition sequence 6 When the burners are ignited a minimum four 4 micro amp DC current will flow through the flame between the sensor electrode and the grounded burner 7 When the...

Page 21: ...the highest position stopping the unit The indoor blower will continue to run for 65 seconds 9 Turn the thermostat system switch to OFF and disconnect all power when servicing the unit START UP PROCED...

Page 22: ...le off and IIC pin 12 will initiate its time delay cycle The compressor and the supply fan will cycle off 10 After a time delay of approximately 3 minutes the compressor control circuits will be ready...

Page 23: ...ster This is especially important in in stallations with extended periods of direct sunlight CONDENSER AND INDUCED DRAFT MOTORS Bearings on the condenser fan motors and the combustion fan motor are pe...

Page 24: ...rable combustion cannot be established within three 3 consecutive ignition attempts If flame is not established within the seven 7 second trial for ignition the gas valve is deenergized 15 second inte...

Page 25: ...excessive supply air temperatures This can be caused by a dirty filter excessive duct static insuffi cient air flow or a faulty limit Check filters total external duct static blower motor blower moto...

Page 26: ...0 6 6903 3 32 6405 2 83 5923 2 41 5434 2 02 4949 1 68 0 8 6717 3 42 6198 2 92 5668 2 45 5152 2 05 1 0 5975 2 99 5418 2 51 1 2 5147 2 55 CFM BHP CFM BHP CFM BHP CFM BHP CFM BHP CFM BHP CFM BHP 0 2 9359...

Page 27: ...SPEED ID FAN MOTOR ELECTRICAL DATA 20 TON ID MOTOR APPL COMPRESSOR ea OD FAN MOTORS ea ID FAN MOTOR VOLTAGE LIMITATIONS VOLTAGE NAMEPLATE MODELS MIN MAX Qty RLA LRA Qty HP RLA HP FLA HP FLA 208 230 60...

Page 28: ...26 APPENDIX C UNIT DIMENSIONS VERTICAL DISCHARGE TOP VIEW 21 60 7 48 22 B C D A Model A B C D 15 Ton 20 Ton 133 1 2 88 7 32 50 9 32 5 5 32...

Page 29: ...27 APPENDIX D WIRING DIAGRAMS...

Page 30: ...2 CC T2 BC EM COMP 2 CM3 CM1 CM2 FC2 FC3 TB2 F C F C F VM 1 2 3 24V 3 2 1 9 6 8 7 4 5 ALS PS GRND LPS1 RD YL RD RD BK PU YL BL 3 1 VMR 4 6 4 2 1 6 YL BL CCH1 CCHR2 PU BK RD OR CC 2 T2 T1 1 L2 L1 T3 L...

Page 31: ...OR EQUIPMENT STATUS PRESSURE SWITCH CHECK BAD SWITCH MAIN LIMIT OPEN STICKING GAS VALVE ANTI CYCLE TIMER 3 MIN COMP PRESSURE SWITCH CHECK GAS PRESSURE FLAME ROLLOUT AUX LIMIT OPEN FLAME SENSOR BAD SWI...

Page 32: ...575 3 ph 60 Hz BL OR OR RD BK RD RD BR BR PU PU RD C F C F FC3 FC2 BK C F FC1 BR BR PU PU PU NOTE 6 BK OR VM 24V 3 1 L2 UNUSED COOL HEAT DI L1 4 5 6 2 3 1 ECON 11 8 12 9 7 10 3 2 1 9 6 8 7 4 5 GV ALS...

Page 33: ...E PLUG TO THE ECONOMIZER COMPARTMENT REMOVE MALE PLUG AND TO BLOWER HOUSING IN RETURN AIR 2 ACCESSORY ECONOMIZER PLUG ADJACENT 4 USE COPPER CONDUCTORSO NLY USE NEC CLASS 2 WIRE 4 3 L1 AND L2 ON IIC CO...

Page 34: ...S2 G WH SEE NOTE 5 S1 RD W1 W2 O YL POWER SUPPLY SEE NOTE 4 208V 240V 3 ph 60Hz SEE NOTE 7 TO THERMOSTAT LOW SPEED CB2 L2 T3 L1 T2 L3 T1 HIGH SPEED CB1 L 2 T3 L1 T2 L3 T1 OR RD BK GY BL YL YL BL GY B...

Page 35: ...LVE A NTI CYCLE TIMER 3 MIN COMP PRES SURE SW ITCH CH ECK GA S PRESSUR E FLAME ROLLOUT AUX LIM IT O PEN FLAM E SENSO R B AD SW ITCH GAS VALVE GA S FLOW REPLACE CONTRO L CHECK FUSE ON CO NTROL CH ECK I...

Page 36: ...S1 RD W1 W2 O YL POWER SUPPLY SEE NOTE 4 460V 575V 3 ph 60Hz SEE NOTE 7 TO THERMOSTAT LOW SPEED CB2 L2 T3 L1 T2 L3 T1 HIGH SPEED CB1 L2 T3 L1 T2 L3 T1 OR RD BK GY BL YL YL BL GY BK RD OR L 3 T3 L 2 CC...

Page 37: ...T REM OVE M ALE PL UG AND TO BLOWE R HOUSING IN RETURN AIR 2 AC CESSORY ECONOMIZER PLU G A DJACENT 4 US E C OPPER CONDU CTORS ONLY USE NEC CLASS 2 W IRE 4 3 L1 AND L2 ON IIC CONTROL IS 24V INPUT 0140...

Page 38: ...o its standard terms and conditions of sale including Limited Product Warranty Consult your local Daikin Applied Representative for warranty details To find your local Daikin Applied Representative go...

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