Product Overview

ManualsBrandsHoneywell ManualsCommercial Thermostats & Controls20 to 30 Vac Discharge air temperature controller (2 Heat/4 Cool)

1 60-2507—3

W7100A-E

G. R. • Rev. 9-93 • ©Honeywell Inc. 1993 • Form Number 60-2507—3

CONTENTS

Specifications ............................................... 2

Ordering Information .................................. 2

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

Operation ................................................... 17

Settings and Adjustments ........................... 23

System Checkout ........................................ 23

W7100A-E

Discharge Air Controller

The microprocessor based W7100 Dis-

charge Air Controller maintains an average

discharge air (DA) temperature in variable air

volume (VAV) cooling systems by modulating

an economizer and sequencing stages of

mechanical cooling. The W7100 is also

applicable to electrical makeup air and other

systems requiring discharge air control of

multistage heating or cooling.

■ Available in cool only, heat only, heat/cool stage

sequencing and modulating heat/cool.

■ Staging capacity of the W7100A-C,E may be

extended using a W7101A Satellite Sequencer.

■ Advanced microprocessor control algorithms

minimize droop.

■ Adjustable control band from 2° F to 16° F [-

17° C to -9° C].

■ M8415 Damper Actuator provides two-position

control: open and closed.

■ Provision for systems without an economizer.

■ Adjustable reset of DA setpoint within range of

5° F to 20° F [3° C to 11° C] upward on cooling,

20° F to 80° F [11° C to 44° C] upward on

heating. Reset signal can be from space sensor

or outdoor air sensor.

■ Adjustable DA setpoint from 40° F to 90° F [4° C

to 32° C] on cool only and heat/cool models;

40° F to 140° F [4° C to 60° C] on heat only and

modulating heat/cool models.

■ C7100 platinum resistance element provides highly

accurate and stable DA temperature sensing.

■ LEDs on W7100 A,B,C, and E panels show

which stages of heating or cooling are on.

■ W7100D has single selectable modulating out-

put, either heat or cool.

Summary of content (28 pages)

PAGE 1
W7100A-E W7100A-E Discharge Air Controller The microprocessor based W7100 Discharge Air Controller maintains an average discharge air (DA) temperature in variable air volume (VAV) cooling systems by modulating an economizer and sequencing stages of mechanical cooling. The W7100 is also applicable to electrical makeup air and other systems requiring discharge air control of multistage heating or cooling. ■ Available in cool only, heat only, heat/cool stage sequencing and modulating heat/cool.
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W7100A-E SPECIFICATIONS • ORDERING INFORMATION Specifications MODELS: W7100 Discharge Air Controller—see Table 1. TABLE 1—W7100 DISCHARGE AIR CONTROLLER MODELS.
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W7100A-E SPECIFICATIONS ACCESSORIES: Model T7047C1025 Quantity As needed S963B1037 As needed C7031G1016 Description Application Remote Set Point Temperature Sensor (15 ohms per degree F, 1495 ohms at 70° F.) Remote Setpoint Potentiometer Discharge air temperature reset from controlled space. Use one or more T7047C1025 with each S963B1037. One Outdoor Air Sensor (2.25 ohms per degree F, 1760 ohms at 70° F.) Reset of discharge air from outdoor air temperature.
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W7100A-E OPERATION Outdoor Reset As an alternative to space temperature reset, outdoor reset may be employed. The advantages of outdoor reset are that it is simple to apply and field wiring is not needed. The disadvantage of outdoor reset is that outdoor temperature change has little effect on the cooling load on many VAV systems; for example, the interior mall of a large shopping center. In this application, the major cooling load consists of solar heat, people and lighting.
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W7100A-E OPERATION Reset from Pneumatic Zone System In most pneumatic systems, the zone dampers are pneumatically controlled. Reset of the discharged temperature can be accomplished from the zone of highest demand by using an L91B1035 Pressure Transducer and an RP913 Hi/ Lo Pressure Signal Discriminator. As shown in Fig. 17, representative zone pneumatic thermostat signals are used as RP913 input signals.
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W7100A-E OPERATION Fig. 19—Outdoor reset. Fig. 20—Series/parallel resistance wiring for W7100 reset. RESISTOR OUTDOOR RESET MECHANICAL SETPOINT FULL RESET SERIES (RS) 6 C7031G1016 RESISTOR (RP) PARALLEL ADJUSTABLE RESET 5° - 20° FOR COOL 20° - 80° FOR HEAT 7 NO RESET T-LOW W7100 TERMINALS M3903 (T-HIGH) and the point at which you desire the W7100 to be fully reset (T-LOW).
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W7100A-E SETTINGS AND ADJUSTMENTS • SYSTEM CHECKOUT Settings and Adjustments SETPOINT KNOB: Set for desired discharge air temperature (55° F to 60° F [13° C to 16° C] is typical). RESET KNOB: Set for desired cool reset (outer scale) or heat reset (inner scale) as required (20° F [11° C] typical). CONTROL BAND KNOB: Set for desired control band. Increasing the control band setting slows down the machinery and increases the temperature deviation.
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W7100A-E SYSTEM CHECKOUT TABLE 6—W7100 CONTROLLER CHECKOUT, COOLING MODE (continued). Step Action Verification 6 Return setpoint knob to 56° F [13° C]. If reset is used, proceed to next step. If not, go to step 10. Cooling LEDs should indicate staging on in about ten seconds.
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W7100A-E SYSTEM CHECKOUT Use Table 7 to perform a checkout of the W7100 Controller in the heating mode. TABLE 7—W7100 CONTROLLER CHECKOUT, HEATING MODE. Step Action Verification 1 Open electrical disconnects on compressors. — 2 Remove red dust cover and connect 195770A Test Plug from 4074EDJ Bag Assembly to W7100 to disable most time delays. Jumper remote setpoint potentiometer terminals P-P1 and jumper reset terminals 6 and 7.
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W7100A-E SYSTEM CHECKOUT Use the applicable sections of Table 8 as a guide in troubleshooting the W7100 Controller. TABLE 8—W7100 TROUBLESHOOTING GUIDE. Problems Possible Cause Corrective Action All heat stages lock on. 1. Remote setpoint terminals open cause setpoint to be interpreted as 143° F [62° C]. 2. Shorted sensor terminals T-T1 interpreted as -2° F [-19° C]. 3. System malfunction. 1. Correct wiring or jumper P-P1. 2. Correct wiring. 3.
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W7100A-E 27 60-2507—3
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W7100A-E Home and Building Control Honeywell Inc. 1985 Douglas Drive North Golden Valley, MN 55422 Home and Building Control Honeywell Limited—Honeywell Limitée 740 Ellesmere Road Scarborough, Ontario M1P 2V9 Printed in U.S.A.