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035-20401-001 Rev. A (0904)

2

Unitary Products Group

INSPECTION

As soon as a unit is received, it should be inspected for possible dam-
age during transit. If damage is evident, the extent of the damage
should be noted on the carrier’s delivery receipt. A separate request for
inspection by the carrier’s agent should be made in writing. See Local
Distributor for more information.

Requirements For Installing/Servicing R-410A Equipment

Gauge sets, hoses, refrigerant containers, and recovery system
must be designed to handle the POE type oils, and the higher
pressures of R-410A.

Manifold sets should be 800 PSIG high side and 250 PSIG low
side with 550 PSIG low side restart.

All hoses must have a 700 PSIG service pressure rating.

Leak detectors should be designed to detect HFC refrigerant.

Recovery equipment (including refrigerant recovery containers)
must be specifically designed to handle R-410A.

Do not use an R-22 TXV.

A liquid-line filter drier is required on every unit.

LIMITATIONS

The unit should be installed in accordance with all National, State and
Local Safety Codes and the limitations listed below:

1.

Limitations for the indoor unit, coil and appropriate accessories
must also be observed.

2.

The outdoor unit must not be installed with any duct work in the air
stream. The outdoor fan is the propeller type and is not designed
to operate against any additional external static pressure.

3.

The maximum and minimum conditions for operation must be
observed to assure a system that will give maximum performance
with minimum service.

4.

This unit is not designed to operate with a low ambient kit. Do not
modify the control system to operate with any kind of low ambient
kit.

5.

The maximum allowable line length for this product is 75 feet.

SECTION III: UNIT INSTALLATION

LOCATION

Before starting the installation, select and check the suitability of the
location for both the indoor and outdoor unit. Observe all limitations and
clearance requirements.

The outdoor unit must have sufficient clearance for air entrance to the
condenser coil, for air discharge and for service access. See Figure 1.

NOTE: 

For multiple unit installations, units must be spaced a minimum

of 18 inches apart. (Coil face to coil face.)

If the unit is to be installed on a hot sun exposed roof or a black-topped
ground area, the unit should be raised sufficiently above the roof or
ground to avoid taking the accumulated layer of hot air into the outdoor
unit.

Provide an adequate structural support.

ADD-ON REPLACEMENT/RETROFIT

When this unit is being used as a replacement for an R-22 unit, it is
required that the outdoor unit, indoor coil, and metering device all be
replaced. The following steps should be performed in order to insure
proper system operation and performance. Line-set change out is also
recommended. 

1.

Change-out of the indoor coil to an approved R-410A coil/ con-
densing unit combination with the appropriate metering device.

2.

Change-out of the line-set when replacing an R-22 unit with an
R410-A unit is highly recommended to reduce cross-contamina-
tion of oils and refrigerants. 

3.

If change-out of the line set is not practical, then the following pre-
cautions should be taken.

Inspect the line set for kinks, sharp bends, or other restrictions,
and for corrosion.

Determine if there are any low spots which might be serving as oil
traps. 

Flush the line set with a commercially available flush kit to
remove as much of the existing oil and contaminants as possible. 

Install a suction line filter-drier to trap any remaining contami-
nants, and remove after 50 hours of operation. 

4.

If the outdoor unit is being replaced due to a compressor burnout,
then installation of a 100% activated alumina suction-line filter
drier in the suction-line is required, in addition to the factory
installed liquid-line drier. Operate the system for 10 hours. Monitor
the suction drier pressure drop. If the pressure drop exceeds 3
psig, replace both the suction-line and liquid-line driers. After a
total of 10 hours run time where the suction-line pressure drop has
not exceeded 3 psig, replace the liquid line drier, and remove the
suction-line drier. Never leave a suction-line drier in the system
longer than 50 hours of run time.

AIR TEMPERATURE DB AT 

OUTDOOR COIL, °F

AIR TEMPERATURE AT 

INDOOR COIL, °F

Min.

Max.

Min.

Max.

Cool

Heat

Cool

Heat

°

WB 

Cool

°

DB 

Heat

°

WB 

Cool

°

DB 

Heat

50

-10

115

75

57

50

1

1. Operation below this temperature is permissible for a short period of 

time, during morning warm-up.

72

80

 FIGURE 1: 

Typical Installation

THERMOSTAT

NEC CLASS 1

WIRING

TO INDOOR
BLOWER

NEC CLASS 2
WIRING

TO COIL

WEATHERPROOF

DISCONNECT SWITCH

48” OVERHEAD
CLEARANCE

24” SERVICE
ACCESS
CLEARANCE

18” FRONT

& SIDES

NOTE:

ALL OUTDOOR WIRING MUST BE WEATHERPROOF

SEAL OPENINGS WITH
PERMAGUM OR EQUIVALENT

Summary of Contents for YZE SERIES

Page 1: ...ractices and hazards involving only property dam age Improper installation may create a condition where the operation of the product could cause personal injury or property damage Improper installatio...

Page 2: ...topped ground area the unit should be raised sufficiently above the roof or ground to avoid taking the accumulated layer of hot air into the outdoor unit Provide an adequate structural support ADD ON...

Page 3: ...a line will result in loss of capacity and other problems caused by insufficient refrigerant flow Slope horizontal vapor lines at least 1 every 20 feet toward the out door unit to facilitate proper oi...

Page 4: ...tem from the vapor service port connection After this con nection has cooled remove the nitrogen source from the liquid fit ting service port 7 Replace the Schrader core in the liquid and vapor valves...

Page 5: ...a vertical run the bulb should be located at least 16 inches from any bend and on the tub ing sides opposite the plane of the bend The bulb should be positioned with the bulb tail at the top so that t...

Page 6: ...hat a mini mum air flow of 325 cfm ton be supplied at all times CFM SELECTION BOARD SETTINGS For proper system operation the CFM Selection Board jumpers must be set properly Refer to the Tabular Data...

Page 7: ...operation the unit must be evacuated and charge weighed in per the marking on the rating plate For the cooling operation the recommended subcooling is typically around 10 F This may vary greatly base...

Page 8: ...ys that are already energized but will not energize any additional relays until the voltage level increases If the voltage drops below approximately 16 VAC the control will imme diately de energize th...

Page 9: ...not be displayed when a fault code is present During the following conditions the control will not energize the X L out put FAULT CODE DISPLAY X L Output The X L terminal of the heat pump control is...

Page 10: ...ored fault codes from the control s memory This practice will enable better troubleshooting and diagnosis of system problems If the stored fault codes are not cleared after the cause of the problem ha...

Page 11: ...be removed and reapplied When the hard lockout condition is reset the control will de energize the LED and X L outputs and respond to thermostat inputs normally Wiring or Setting Related Lockouts The...

Page 12: ...ing cycle The control will initiate a defrost cycle every 6 hours accumulated com pressor run time to recirculate refrigerant lubricants This forced defrost timer will be reset and restarted following...

Page 13: ...es Recycling 24VAC to the control Shorting the TEST input pins If the Y2 LOCK jumper is in the OFF position the control will not imple ment second stage anticipation mode This results in second stage...

Page 14: ...uid line temperature Therefore if the control energizes Y2 OUT because the outdoor ambient temperature is greater than or equal to 50F or because the liquid line temperature exceeds the curve for the...

Page 15: ...ode If the other exit conditions are met while the unit is in defrost mode the control will complete the defrost cycle and then exit the forced second stage feature During defrost operation the contro...

Page 16: ...re is greater than the bal ance point setting the control will not energize the auxiliary heat out puts However the control shall ignore the balance point setting and energize auxiliary heat under som...

Page 17: ...t the control will de energize the compressor outputs and energize W1 OUT and W2 OUT immediately Table 11 describes the auxiliary heat operation for fossil fuel mode Bonnet Sensor Fossil Fuel Mode The...

Page 18: ...this document for detailed information The Y2 Lock jumper on the control is shown in figures 11 14 The fac tory places the Y2 Lock jumper in the ON position If the jumper is removed the control will...

Page 19: ...When applicable instruct the owner that the compressor is equipped with a crankcase heater to prevent the migration of refrigerant to the compressor during the OFF cycle The heater is energized only...

Page 20: ...404 11 105 412 6 416 9 426 12 431 11 110 441 7 445 9 454 12 458 11 115 471 8 475 10 482 12 487 11 120 503 9 507 10 512 11 516 11 125 536 10 540 10 543 11 546 10 TABLE 15 15Z48HP Subcooling Charging C...

Page 21: ...035 20401 001 Rev A 0904 Unitary Products Group 21 SECTION X WIRING DIAGRAM FIGURE 15 Wiring Diagram...

Page 22: ...035 20401 001 Rev A 0904 22 Unitary Products Group NOTES...

Page 23: ...035 20401 001 Rev A 0904 Unitary Products Group 23...

Page 24: ...ct to change without notice Printed in U S A 035 20401 001 Rev A 0904 Copyright by York International Corp 2004 All rights reserved Supersedes Nothing Unitary 5005 Norman Product York OK Group Drive 7...

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