Honeywell W7080A - User Manual

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Summary

Honeywell Multizone Control System Overview

W7080 A Load Analyzer Functionality

Provides SPDT relay switching for heating/cooling stages and modulating output.

Economizer and Cooling Control

Uses M745K/M745L motor for first stage cooling with outdoor air.

System Power Interruption Behavior

System switches stages off upon power interruption and on upon restoration.

Power Supply Protection

Power supplies are short-circuit protected against 24 Vdc shorts.

Night Setback and Cooling Shut-down

Enables night setback and cooling shut-down for zones via a time clock.

System Specifications and Components

System Component Descriptions

Details various system components including sensors, thermostats, limit controllers, and analyzers.

Electrical and Contact Ratings

Covers voltage, frequency, power consumption, and SPDT relay contact ratings.

System Input and Output Signals

Lists DC voltage signals for system inputs and outputs with relevant components.

Stage Differentials and Thermostat Dead Band

Explains stage differentials and thermostat dead band settings as depicted in Figure 1.

Economizer and Control Parameters

Economizer Mixed Air Limit

Outdoor air damper modulation based on mixed air temperature setpoint.

Integrator Minimum Output

Selectable minimum output for fan motor speed control.

Zone Discharge Sensor Authority

Defines how zone discharge sensor changes affect voltage.

Ambient Temperature Rise

Specifies operating and shipping temperature ranges.

Cold Deck Low Limit

Limits cold deck temperature to selectable setpoints.

Hot Deck High Limit

Limits hot deck temperature to selectable setpoints.

System Accessories and Important Notes

Transformer Usage and Isolation

Guidelines for transformer use, isolation, and grounding.

Motor and Linkage Components

Descriptions of damper linkage, valve linkage, and potentiometers.

Modulating Water Valves

Guidance on using valves with Super Modutrol motors.

Night Setback Resistor Values

Lists resistor values for achieving specific heating setbacks.

System Component Protection

Details on the metal cover for protecting system components.

Summary

Honeywell Multizone Control System Overview

W7080 A Load Analyzer Functionality

Provides SPDT relay switching for heating/cooling stages and modulating output.

Economizer and Cooling Control

Uses M745K/M745L motor for first stage cooling with outdoor air.

System Power Interruption Behavior

System switches stages off upon power interruption and on upon restoration.

Power Supply Protection

Power supplies are short-circuit protected against 24 Vdc shorts.

Night Setback and Cooling Shut-down

Enables night setback and cooling shut-down for zones via a time clock.

System Specifications and Components

System Component Descriptions

Details various system components including sensors, thermostats, limit controllers, and analyzers.

Electrical and Contact Ratings

Covers voltage, frequency, power consumption, and SPDT relay contact ratings.

System Input and Output Signals

Lists DC voltage signals for system inputs and outputs with relevant components.

Stage Differentials and Thermostat Dead Band

Explains stage differentials and thermostat dead band settings as depicted in Figure 1.

Economizer and Control Parameters

Economizer Mixed Air Limit

Outdoor air damper modulation based on mixed air temperature setpoint.

Integrator Minimum Output

Selectable minimum output for fan motor speed control.

Zone Discharge Sensor Authority

Defines how zone discharge sensor changes affect voltage.

Ambient Temperature Rise

Specifies operating and shipping temperature ranges.

Cold Deck Low Limit

Limits cold deck temperature to selectable setpoints.

Hot Deck High Limit

Limits hot deck temperature to selectable setpoints.

System Accessories and Important Notes

Transformer Usage and Isolation

Guidelines for transformer use, isolation, and grounding.

Motor and Linkage Components

Descriptions of damper linkage, valve linkage, and potentiometers.

Modulating Water Valves

Guidance on using valves with Super Modutrol motors.

Night Setback Resistor Values

Lists resistor values for achieving specific heating setbacks.

System Component Protection

Details on the metal cover for protecting system components.

The Honeywell Multizone Control System is a solid-state system designed for component field replacement of the Ranco EA3 Lodapt System. It provides comprehensive control for multizone HVAC applications.

Function Description

The basic system controls up to 12 zone dampers, 3 heating stages, 3 cooling stages, an integrated economizer, and modulating valves for hot and chilled water. Optional units can expand control to include up to 12 additional zones, 5 stages of electric heat, a variable air volume (VAV) system fan, and a fourth stage of cooling.

The W7080A Load Analyzer (Ranco EA3) is a central component, providing SPDT relay switching for three stages of heating and three stages of cooling. It also delivers a modulating output to economizer and valve motors, responding to the highest heating and cooling demand from zone thermostats. The analyzer serves as the source of 24 Vdc power for zone thermostats and sensors.

Zone dampers are directly controlled by a modulated DC voltage signal from the zone thermostat, which is modified by a zone discharge sensor. Pilot duty SPDT relays manage heating and cooling stages.

The economizer utilizes an M745K or M745L motor to provide true first-stage cooling, prioritizing outdoor air whenever possible. The system is designed to switch all stages off upon power interruption and switch all stages on when power is restored. Compressor turn-on time delays must be incorporated for each compressor.

Power supplies within the W7080A Load Analyzer and W7084A Zone Adder are short-circuit protected, meaning short circuits of 24 Vdc from either unit will not damage their power supplies. Night setback and cooling shut-down for individual or all zones can be achieved by adding a time clock.

System Components

C7046B Temperature Sensor (Ranco TR1-1001): A non-averaging type with a 6-inch (152 mm) probe, suitable for ducts where space is limited.
C7100B Averaging Temperature Sensor (Ranco TR1-1002,-1003): Installed in hot deck, cold deck, and mixed air ducts to provide limit signals for the limit controller. Also used in zone discharge ducts for anticipation with the T7080 Thermostat.
H205A Enthalpy Controller (Ranco (15)): Senses the heat content (temperature and humidity) of outdoor air, enabling the use of outdoor air for free cooling.
S7666A Simulator (Ranco TEI): A portable unit for system checks, substituting adjustable DC voltage for zone thermostat and sensor signals.
T7080A,B Solid State, Dual Setpoint Thermostat (Ranco TR3, TR4): Modulates zone dampers and supplies load demand signals to the load analyzer. Features a single voltage ramp design with a variable 3 to 30°F (1.7 to 16.7°C) deadband. T7080A has a built-in sensor; T7080B requires a remote sensor.
W7081A Limit Controller (Ranco EA5-G3002): Provides economizer control in addition to hot and cold deck selectable limits. Saves energy by maintaining selected temperature limits of hot and cold decks when zone demands are reduced.
W7082A Integrator Analyzer (Ranco EA5-C6001-35): An optional unit that controls the system blower in VAV systems in response to zone demand. It reduces fan output during decreased demand, saving energy.
W7083A Electric Heat Sequencer (Replaces Ranco EA5-C0501): An optional unit that switches up to five ON/OFF stages of electric heat, providing stage turn-on delay on power restoration.
W7084A Zone Adder (Ranco EA5-C9001,-C9002): An optional unit that allows the addition of up to 12 zones to the system.
195325B Fourth Stage Cooling Board (Ranco EA5-C9100): An optional unit that permits the addition of a fourth stage of cooling to the system.

Technical Specifications

Electrical Ratings: 24 Vac, 50/60 Hz.
Maximum Power Consumption:
- W7080A: 10 VA
- W7081A: 0.29 VA
- W7082A: 1.5 VA
- W7083A: 1.4 VA
- W7084A: 3 VA
Relay Contact Ratings (SPDT pilot duty relays) for W7080A, W7083A, 195325B:
- Normally open: 24 Vac (240 VA inrush, 60 VA running); 120/240 Vac (750 VA inrush, 100 VA running).
- Normally closed: 24 Vac (75 VA inrush, 30 VA running); 120/240 Vac (240 VA inrush, 40 VA running).
- Note: VA ratings are not valid when maximum load is connected to both normally open and normally closed contacts.
System Input Signals (Vdc):
- 2-22 Vdc from T7080A,B to W7080A.
- 2-12 Vdc (LO) and 12-22 Vdc (HI) from W7080A, W7084A to W7081A.
- 2-12 Vdc from W7080A, W7081A to W7083A.
- 12-24 Vdc from W7080A, W7081A to 195325B.
- 14-17 Vdc from W7081A to M745K,L.
- 4-7 Vdc from W7081A to M744D, M745G,P.
System Output Signals (Vdc):
- 2.22 Vdc from T7080A to W7080A, W7082A, W7084A, M734.
- 10.5-13.5 Vdc from W7080A, W7082A, W7084A, M734 to W7081A, M734.
- 2-12 Vdc from W7080A, W7084A (LO) to W7081A, W7083A, 195325B.
- 12-22 Vdc from W7080A, W7084A (HI) to W7081A, W7083A, 195325B.
- 14-17 Vdc and 4-7 Vdc from W7081A to M745K,L, M744D, M745G,P.
- 0 to -10 Vdc from W7082A to Inverter (VAV fan motor control).
Stage Differentials: Stages overlap by 0.3°F (0.2°C).
Dead Band: 3-30°F (1.7-16.7°C).
Economizer Mixed Air Limit: Selectable setpoints of 50°F, 55°F, or 60°F (10°C, 12.8°C, or 15.6°C) with a 10°F (5.6°C) fixed throttling range.
Integrator Minimum Output: Selectable from 0 to 8 Vdc (0 to 60 percent fan motor speed).
Zone Discharge Sensor Authority: 20:1 ratio (a 20°F [11.1°C] rise at the zone discharge sensor produces a voltage change equal to a 1°F [0.5°C] rise at the space thermostat).
Ambient Temperature Rise: Operating: -40 to 150°F (-40 to 65°C); Shipping: -30 to 150°F (-34 to 65°C).
Cold Deck Low Limit: Selectable setpoints of 45°F, 50°F, or 55°F (7.2°C, 10°C, or 12.8°C).
Hot Deck High Limit: Selectable setpoints of 90°F, 110°F, or 130°F (32.2°C, 43.3°C, or 54.4°C).
Nonspring Return Motors (M734J, M744D): Solid-state balance relay, 24 Vac, 50/60 Hz.
- M734J: 35 lb.-in. (4 N.m) torque over 160-degree stroke. Modulates zone discharge damper.
- M744D: 150 lb.-in. (17 N.m) torque with 90 and 160-degree nonadjustable stroke. Modulates hot water or chilled water valves. Requires separate power supply.
Spring Return Motors (M745G,K,L,P): Solid-state balance relay, requires separate 24 Vac, 50/60 Hz power supplies.
- M745K or M745L: Operates economizer damper.
- M745G,P: Modulates hot water or chilled water valves. Requires 4074EAC Resistor Kit.
Transformers (System Accessories): AT20-20 VA; AT7240 VA; AT88-75 VA.
1914448 Metal Cover: Protects W7080A, W7081A, W7082A, W7083A, W7084A components when mounted on open surfaces. Dimensions: 6 5/8 in. long, 4 5/16 in. wide, 4 13/16 in. high (168.3 x 108.5 x 122.2 mm).

Usage Features

Mounting: W7080A, W7081A, W7082A, W7083A, W7084A units attach with four screws through mounting holes in the base. The 195325B Fourth Stage Cooling Board can be mounted on a flat surface.
Economizer Mixed Air Sensor (C7100B or C7046B): Can be mounted in the cold deck if closing the economizer during mechanical cooling is desired. Can also be used as a remote return air sensor with T7080B Zone Thermostat.
Q209A Minimum Position Potentiometer: Mounts directly on M734, M744, M745 motors; controls minimum open position of damper.
Q605 Damper Linkage: Connects motor to damper, includes motor crank arm.
Q618 Valve Linkage: Connects Modutrol motor to modulating hot or chilled water valves.
S963A Remote Minimum Position Potentiometer: Provides remote manual control of minimum open position of economizer motor.
Modulating Water Valves: Use appropriate valve with Super Modutrol motor and Q618 Linkage for proportional control of hot or chilled water flow.
Compressor Ambient Lockout Thermostat: Prevents compressor operation when outdoor air temperature falls below the economizer setpoint. (T675A Temperature Controller, L6018C Temperature Controller).
Economizer Changeover Controller: Holds economizer at minimum position when outdoor air temperature or enthalpy is above the controller setpoint. (H205A1038 or H205A1046 Enthalpy Controller, T675A Temperature Controller, L6018C Temperature Controller).
Night Setback: Provides heating setback of 6 to 22°F (3.3 to 12.2°C). Requires connection of a 1% resistor and S6005 Time Clock contact between Terminals 3, 7 or 6; and 5 of T7080A or T7080B Thermostat. Resistors available for different setbacks: 802139BAAC (10.0 kΩ) for 6°F (3.3°C), 802139EJHB (4.87 kΩ) for 10°F (5.6°C), 802139CGHB (2.67 kΩ) for 14°F (7.8°C), 802139BEDB (1.43 kΩ) for 18°F (10°C), 802139GJBA (681 Ω) for 22°F (12.2°C).
Morning Warm-up Thermostat: Holds outdoor air damper fully closed following night setback until return air temperature exceeds selected setpoint. (T675A Temperature Controller, L6018C Temperature Controller).
S43 Sail Switch: Activates circuits when minimum airflow is maintained in the duct, deactivating below minimum airflow.

Maintenance Features

Time Delay Relays: To improve system stability and minimize energy use, five-minute turn-on time delays should be added to all heating and cooling loads. These relays should be wired between cooling and heating stage switching outputs (W7080A Load Analyzer, W7083A Electric Heat Sequencer, and 195325B Fourth Stage Cooling Board) and the heating and cooling equipment.
Transformer Usage: The transformer used to power the W7080A Load Analyzer can also power stage relays in the W7083A Electric Heat Sequencer (if used). M744 and M745 motors each require a separate transformer to ensure electrical isolation. Never ground the secondary of any transformer used to power any system component.