Carrier VVT 33ZC Installation, Start-up And Configuration Instructions

Contents

2This book will discuss installation and wiring of the bypasscontroller and bypass actuator. The bypass damper and ductsystem should already be correctly sized and installed. The by-pass actuator should be sized to match the bypass damper.Carrier provides system software that can be used to design thesystem and choose the correct dampers and actuators based onthe application.Bypass Controller Hardware — The bypass control-ler consists of the following hardware:• control module• plastic enclosure with integrated actuator• one no. 8 x 3/4-in. self-drilling sheet metal screwFigure 1 shows the bypass controller physical details.Field-Supplied Hardware — Each bypass controllerrequires the following field-supplied components to completeits installation:• damper• damper actuator (if high-torque actuator is required)• transformer — 24 vac, 40 va (standard applications)• duct temperature sensor (33ZCSENDAT) with grommet(to secure DAT sensor to duct)DUCT TEMPERATURE SENSOR (DAT) — The bypasscontroller must be connected to a field-supplied duct tempera-ture sensor (part number 33ZCSENDAT) to monitor the tem-perature of the air delivered by the air source.Mount Bypass ControllerLOCATION — The bypass controller should be located on ornear the bypass damper in a ceiling area where accessible.When an external high-torque actuator is used, the bypasscontroller is mounted on the shaft of the damper. Select alocation which will be safe from water damage and allowsufficient access for service and wiring. For service access,there should be at least 6 in. of clearance between the front ofthe bypass controller and adjacent surfaces. Refer to Fig. 1-3.MOUNTING — Perform the following steps to mount thebypass controller:1. Visually inspect the damper and determine the direc-tion in which the damper shaft moves to open thedamper — clockwise (CW) or counterclockwise(CCW).If the damper rotates CCW to open, it does not requireany configuration changes.If the damper rotates CW to open, then the damperactuator logic must be reversed. This is done in thesoftware when performing system start-up and dampercalibration test. Do not attempt to change damper rota-tion by changing wiring. This will upset the damperposition feedback potentiometer readings.2. Rotate the damper shaft to the fully closed position.3. Press the release button on the actuator and rotate theclamp in the same direction that was required to closethe damper in Step 2.4. Press the actuator release button and rotate the actuatorback one-position of graduation. Release the buttonand lock the actuator in this position.5. Mount the bypass controller to the terminal by slidingthe damper shaft through the actuator clamp assembly.See Fig. 2 for details. Remove the controller wiringaccess cover. Secure the controller by installing thescrew provided through the grommet in the anti-rotation slot. Detach the grommet from the slot so itcan slide from side to side. Be sure the floating grom-met is in the center of the slot. FAILURE TOCENTER THE GROMMET MAY CAUSE THEACTUATOR TO STICK OR BIND.6. Tighten the actuator clamp assembly to the dampershaft. Secure by tightening the two 8-mm nuts.7. If the damper has less than 90 degrees of travelbetween the fully open and fully closed positions, thena mechanical stop must be set on the actuator. Themechanical stop prevents the damper from openingpast the maximum damper position. To set themechanical stop, perform the following procedure:a. Press the actuator release button and rotate thedamper to the fully open position.b. Using a No. 1 Phillips screwdriver, loosen theappropriate stop clamp screw and move the stopclamp so that it contacts the edge of the cam onthe actuator.c. Secure the stop clamp in this position by tighten-ing the screw.8. Verify that the damper opens and closes. Press theactuator release button and rotate the damper. Verifythat the damper does not rotate past the fully openposition. Release the button and lock the damper in thefully open position.9. Replace wiring access cover.Connect the Power Transformer — An individual,field-supplied, 24-vac power transformer is required for eachbypass controller. Transformers must be UL (Underwriters’Laboratories) Class 2 rated. Standard applications require a24 vac transformer, rated at 40 va minimum. All transformersecondaries are required to be grounded. Use only strandedcopper conductors for all wiring to the bypass controller.Wiring connections must be made in accordance with NEC(National Electrical Code) and local codes. Ground one side ofthe transformer secondary at the transformer location. Connectthe grounded side of the transformer to J1-2. Connect the liveside of the transformer secondary to J1-1. Connect an 18-gage,green ground wire from terminal J1-3 to the metal chassis ofthe unit.The power supply is 24 vac ± 10% at 40 va (50/60 Hz).For bypass controllers, the power requirement sizing allowsfor the bypass actuator. The bypass damper actuator is limitedto 20 va.NOTE: Do not run sensor or communication wiring in thesame conduit with line-voltage wiring.Perform the following steps to connect the powertransformer:1. Install the field-supplied transformer in an electricalenclosure that conforms to NEC and local codes.2. Connect 24 vac from the transformer as shown in theapplicable wiring diagram (Fig. 4). Be sure to observepolarity when connecting the transformer power. Thegrounded terminal must be connected to the transformerground terminal as shown.