Johnson Controls ZU Series

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R-410A

ZU SERIES W/SMART EQUIPMENT™

6-1/2 - 12-1/2 Ton

60 Hertz

5566216-BIM-B-1118

Table of contents

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Preceding installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Limitations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Unit components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Clearances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Rigging and handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Ductwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Side panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Condensate drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Power and control wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Optional electric heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Optional gas heat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Options and accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Optional variable air volume . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Optional hot gas bypass (HGBP). . . . . . . . . . . . . . . . . . . . . . . 37

Economizer sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Dry bulb changeover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Single enthalpy changeover . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Dual enthalpy changeover. . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Auto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Free cooling operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Power exhaust. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Smart Equipment™ economizer board . . . . . . . . . . . . . . . . . . 39

Airflow performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Air balance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Checking air quantity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Cooling sequence of operation . . . . . . . . . . . . . . . . . . . . . . . . 53

Cooling operation errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Electric heating sequence of operations . . . . . . . . . . . . . . . . . 56

Electric heat operation errors . . . . . . . . . . . . . . . . . . . . . . . . 56

Gas heating sequence of operations. . . . . . . . . . . . . . . . . . . . 57

Gas heating operation errors . . . . . . . . . . . . . . . . . . . . . . . . 58

Cooling start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Gas heat start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Checking gas heat input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Charging the unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Navigation components for the Smart Equipment™ control board . . 62

Smart Equipment™ unit control board . . . . . . . . . . . . . . . . . . . . . 63

Start-up sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

List of tables

1 Component location table . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2 ZU-06 through -12 unit limitations . . . . . . . . . . . . . . . . . . . . . . 8

3 Weights and dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4 ZU-06 through -12 unit accessory weights . . . . . . . . . . . . . . 10

5 ZU-06 through -12 unit physical dimensions . . . . . . . . . . . . . 11

6 Gas inlet and drain components . . . . . . . . . . . . . . . . . . . . . . 12

7 ZU-06 through -12 unit clearances . . . . . . . . . . . . . . . . . . . . 12

8 Side duct dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

9 Left/end duct dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

10 Roof curb components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

11 Control wire sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

12 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

13 ZU-06 through -12 physical data . . . . . . . . . . . . . . . . . . . . . . 30

14 Electric heat minimum supply air . . . . . . . . . . . . . . . . . . . . . . 32

15 Gas pipe sizing - capacity of pipe . . . . . . . . . . . . . . . . . . . . . 33

16 Gas heat minimum supply air . . . . . . . . . . . . . . . . . . . . . . . . 33

17 Supply air limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

18 Altitude/temperature correction factors . . . . . . . . . . . . . . . . . 44

19 Airflow performance - side duct application . . . . . . . . . . . . . 46

20 Airflow performance - bottom duct application . . . . . . . . . . . 48

21 RPM selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

22 Indoor blower specifications . . . . . . . . . . . . . . . . . . . . . . . . . 50

23 Power exhaust specifications . . . . . . . . . . . . . . . . . . . . . . . . 50

24 Motor sheave datum diameters . . . . . . . . . . . . . . . . . . . . . . 52

25 Additional static resistance . . . . . . . . . . . . . . . . . . . . . . . . . . 53

26 Electric heat limit setting 50 in. cabinet . . . . . . . . . . . . . . . . . 56

27 Electric heat limit setting 42 in. cabinet . . . . . . . . . . . . . . . . . 57

28 Electric heat anticipator setpoints . . . . . . . . . . . . . . . . . . . . . 57

29 Gas heat limit control settings . . . . . . . . . . . . . . . . . . . . . . . . 59

30 Gas heat anticipator setpoints . . . . . . . . . . . . . . . . . . . . . . . 59

31 Gas rate cubic feet per hour . . . . . . . . . . . . . . . . . . . . . . . . . 61

32 Gas heat stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

33 Cable for FC buses and SA buses in order of preference . . 69

34 Ignition control flash codes . . . . . . . . . . . . . . . . . . . . . . . . . . 69

List of figures

1 Unit shipping bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Condenser covering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3 Compressor section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4 ZU component location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5 Unit 4 point load weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

6 Unit 6 point load weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

7 Center of gravity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

8 ZU-06 through -10 physical dimensions . . . . . . . . . . . . . . . . 10

9 ZU-12 physical dimensions . . . . . . . . . . . . . . . . . . . . . . . . . 11

10 ZU-06 through -12 unit bottom duct openings . . . . . . . . . . . 13

11 ZU-06 through -12 unit electrical entry . . . . . . . . . . . . . . . . . 14

12 ZU-06 through -10 unit side duct openings . . . . . . . . . . . . . 14

13 ZU-12 unit side duct openings . . . . . . . . . . . . . . . . . . . . . . . 15

14 ZU-06 through -12 unit left/end duct opening . . . . . . . . . . . . 15

15 ZU-06 through -12 roof curb . . . . . . . . . . . . . . . . . . . . . . . . . 16

16 ZU-06 through -12 transition roof curb . . . . . . . . . . . . . . . . . 16

17 Side panels with hole plugs . . . . . . . . . . . . . . . . . . . . . . . . . 17

18 Return downflow plenum with panel . . . . . . . . . . . . . . . . . . . 17

19 Discharge panel in place . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

20 Side panels for economizer hood tops . . . . . . . . . . . . . . . . . 18

21 Condensate drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

22 Field wiring disconnect - cooling unit with or without electric

heat and all units with a VFD option . . . . . . . . . . . . . . . . . . . 20

23 Field wiring disconnect - cooling unit with gas heat without a

VFD option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

24 Typical electronic thermostat field wiring . . . . . . . . . . . . . . . 21

25 Side entry gas piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

26 Bottom entry gas piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

27 Simplified VFD wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

28 SE-ECO1001-0 economizer controller . . . . . . . . . . . . . . . . . 39

29 Belt adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

30 Altitude/temperature correction factors . . . . . . . . . . . . . . . . 44

31 Dry coil delta P . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

32 Typical flame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

33 Typical gas valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

34 Unit control board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Main Page

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Do you have a question about the Johnson Controls ZU Series and is the answer not in the manual?

This document describes the ZU Series SMART EQUIPMENT™ 6.5-12.5 Ton unit, a single-package air conditioner with optional gas heating designed for outdoor installation on rooftops or slabs for non-residential use. The units can be equipped with factory or field-installed electric heaters for heating applications.

Function Description

The ZU Series units are fully assembled with rigid, permanently attached base rails. All piping, refrigerant charge, and electrical wiring are factory installed and tested. The units require electric power, gas supply (where applicable), and duct connections. Electric heaters use nickel-chrome elements and single-point power connection. The Smart Equipment™ control board allows the cooling system to operate down to 0°F in comfort cooling applications, especially when an economizer is included. For process cooling applications (e.g., computer rooms), additional accessories may be needed for stable operation at temperatures below 30°F.

Important Technical Specifications

The units are available in various nominal tonnages: 6.5, 7.5, 8.5, 10, and 12.5 tons.

Condenser Fan Data: All models feature 2 condenser fans with 24-inch diameters, propeller type, and direct drive. The 6.5, 7.5, 8.5, and 10-ton units have two 1/3 HP motors, while the 12.5-ton unit has four 1/3 HP motors. All have a single speed with RPMs ranging from 850 to 1110 and total CFM from 6700 to 14000.
Evaporator Fan Data: All models have one centrifugal belt-drive evaporator fan. Fan sizes are 12x12 inches for 6.5 and 7.5-ton units, and 15x15 inches for 8.5, 10, and 12.5-ton units. Motor HP ranges from 1-1/2 to 5 HP, with RPMs from 1725 to 1725.
Filters: All units use 4 filters, with sizes varying by model (24x16x2, 24x16x4, 24x20x2, 24x20x4 inches). Standard filters are 2-inch throwaway MERV 3, with optional 2-inch pleated MERV 8 or 4-inch pleated MERV 13.
Electrical Data: Units operate on 208/230V, 460V, or 575V, 3-phase, 60Hz. Minimum Circuit Ampacity (MCA) and Max Fuse/Breaker sizes vary significantly based on tonnage, voltage, and electric heat options. For example, a 6.5-ton unit (208V) with no electric heat has an MCA of 48.9 amps and a max fuse size of 60 amps. With 54kW electric heat, the MCA increases to 149.4 amps and max fuse size to 150 amps.
Gas Heat Data: Available in N12, N18, and N24 sizes. Minimum supply air CFM ranges from 1950 to 3750, and maximum supply air CFM from 3250 to 6250 for both cooling and heating.
Physical Dimensions: Units vary in height (42 to 50 3/4 inches), width (89 to 119 1/2 inches), and depth. Weights range from 900 to 1285 lbs (shipping) and 895 to 1280 lbs (operating).

Usage Features

Installation: Units are designed for outdoor installation on a rooftop or slab. Condenser coils require an unlimited air supply. For ground-level installation, a level concrete slab at least 4 inches thick and 6 inches wider than the unit base rails is required. Roof structures must support the unit's weight and options.
Ductwork: Ductwork must be designed and sized according to ACCA Manual D or other recognized authorities. Connections should use flexible joints to minimize noise. Side duct openings are covered upon shipment; for bottom duct applications, no changes are needed.
Electrical Wiring: Field wiring, fuses, and disconnects must conform to NEC, CSA C221, and local ordinances. Units must be electrically grounded. Voltage tolerances must be maintained at compressor terminals. Water-proof connectors are required for electrical and control wiring.
Thermostat Wiring: Thermostat should be installed on an inside wall, approximately 56 inches above the floor, away from drafts, sun exposure, or heat sources. The Smart Equipment™ control board has a jumper between R and OCC terminals; removing this jumper allows thermostat or EMS control of the Occupied mode.
Gas Connection: Gas supply lines must be routed within the roof curb. A drip leg and ground joint union are required. Wrought iron or steel pipe should be used for gas lines, with special pipe dope for LP gas. All connections must be checked for leaks using a soap solution.
Economizer Sequences: The economizer can be driven by minimum position, free cooling, economizer loading, and minimum outdoor air supply. Free cooling options include dry bulb changeover, single enthalpy, dual enthalpy changeover, and Auto mode.
Power Exhaust: Power exhaust can be factory-installed or field-installed. It energizes when the economizer output is above the economizer damper position for the exhaust fan.
VAV Startup and Control: For Variable Air Volume (VAV) units, the VFD is controlled by duct static pressure. The unit must be in Occupied Mode for operation, and VAV boxes must be driven to the full-open position during heating to ensure adequate airflow.
Cooling Operation: The unit monitors evaporator low limit, high-pressure, and low-pressure switches. If a fault occurs, the associated compressor is de-energized, and an Anti-Short Cycle Delay (ASCD) is initiated.
Electric Heat Operation: Two-stage heating is available. The unit monitors temperature limit switches. If the limit switch opens due to inadequate airflow, the heater shuts down, and the blower energizes.
Gas Heat Operation: Two-stage heating is available. The unit monitors pressure switches and roll-out switches. Manifold gas pressure can be adjusted for 60% and 100% input stages.

Maintenance Features

Air Balance: The supply air blower motor speed and belt tension must be adjusted to meet specific static and CFM requirements. Sheave alignment should be verified, and set screws tightened after adjustments.
Checking Air Quantity: Airflow can be measured by drilling holes in the return and supply air ducts, inserting metal tubing, and using an inclined manometer to determine pressure drop across the evaporator coil.
Compressor Protection: Compressors have inherent internal protection against abnormal temperature rise. The UCB incorporates ASCD to prevent rapid cycling and imposes a minimum run time.
Flash Codes: The Ignition Control Board (ICB) initiates flash codes for system errors, which can be reset by lowering the thermostat setting below the conditioned space temperature.
Control Board Access: Control points can be accessed via the local LCD on the unit control board or through a Mobile Access Portal (MAP) Gateway.
USB Connector: The UCB includes a USB connector for backup, restoration, copying of board parameters, and software updating via a flash drive.