User manual HONEYWELL W7750B

[. . . ] W7750A, B CONSTANT VOLUME AHU CONTROLLER ([FHO 352'8&7 '(6&5, 37, 21 The W7750 is the Constant Volume Air Handling Unit (CVAHU) Controller in the Excel 10 product line family. The CVAHU is a Free Topology Transceiver (FTT) LonMark compliant device designed to control single zone and heat pump air handlers. W7750 systems control the space temperature in a given zone by regulating the heating and cooling equipment in the air handler that delivers air to that space. The W7750 air handler is typically an all-in-one packaged unit, located on the roof of the building. [. . . ] For nonplenum areas, US part AK3781 (one pair) or US part AK3782 (two pair) can be uses. In plenum areas, US part AK3791 (one pair) or US part AK3792 (two pair) can be used. Communications wiring can be run in a conduit, if needed, with QRQVZLWFKHG 24 Vac or sensor wiring. If a longer E-Bus network is required, a Q7740A 2-way or Q7740B 4-way repeater can be added to extend the length of the E-Bus. A Q7751A Router can be added to partition the system into two segments and effectively double the length of the E-Bus. Only one router is allowed with each Excel 10 Zone Manager, and each network segment can have a maximum of one repeater. Pull the cable to each controller on the E-Bus and connect to communication terminals 14 and 15 (W7750A, B). 5 95-75211 (;&(/ :$% &2167$17 92/80( $+8 &21752//(5 )LJ 7HUPLQDWLRQ PRGXOHV NOTE: When attaching two or more wires to the same terminal, other than 14 AWG (2. 0 mm2), be sure to twist them together. Deviation from this rule can result in improper electrical contact. Wire to the terminal blocks as follows: Strip 1/2 in. Insert the wire in the required terminal location and tighten the screw to complete the termination. If two or more wires are being inserted into one terminal location, twist the wires together a minimum of three turns before inserting them. Cut the twisted end of the wires to 3/16 in. (5 mm) before inserting them into the terminal and tightening the screw. Pull on each wire in all terminals to check for good mechanical connection. :LULQJ 'HWDLOV The W7750A Controller has the terminal arrangement shown in Fig. 9 through 15 illustrate W7750A, B Controller wiring for various configurations. Connection for operator access to the E-Bus is provided by plugging the Serial LonTalk Adapter (SLTA) connector into the E-Bus jack. NOTE: If an Excel 10 W7750A, B Controller or Zone Manager is not connected to a good earth ground, the controllers internal transient protection circuitry is compromised and the function of protecting the controller from noise and power line spikes cannot be fulfilled. This could result in a damaged circuit board and require replacement of the controller. Refer to installation diagrams for specific wiring. )LJ $WWDFKLQJ WZR RU PRUH ZLUHV DW WHUPLQDO EORFNV 95-75211 6 (;&(/ :$% &2167$17 92/80( $+8 &21752//(5 HEAT 1 HEAT 1 HEAT 2 COMP 1 COMP2 HEAT 2 COMP 1 COMP2 3 FAN LOAD AND CONTROLLER POWER 24 VAC FAN LOAD POWER C 24 VAC H CONTROLLER POWER 24 VAC LINE AC + - 31 W1 30 W2 29 Y1 28 Y2 27 G 26 25 24 Rc 23 Rh 22 VAC 24 21 VAC 24COM 20 19 18 17 16 NETWORK DO NOT USED + - 31 W1 30 W2 29 Y1 28 Y2 27 G 26 25 24 Rc 23 Rh 22 VAC 24 21 VAC 24 COM 20 19 18 17 16 NETWORK DO NOT USED W7750A CONSTANT VOLUME AHU CONTROLLER GROUND GROUND GROUND WALL MODULE SENSOR GROUND SET PT EARTH GROUND AI-1 OHM BYPASS LED NOT USED DI- 1 DI- 2 NOT USED SENSOR GROUND BYPASS SET PT EARTH GROUND DI- 1 DI- 2 2 1 TIME CLOCK E-BUS AI-1 OHM E-BUS 14 2 15 J3 1 2 3 4 5 6 7 8 9 10 11 12 13 DISCHARGE AIR TEMP 1 TIME CLOCK E-BUS 987654321 SENSOR BYPASS SET PT LED E-BUS GND E-BUS 2 JACK FOR E-BUS NETWORK ACCESS DISCHARGE AIR TEMP 987654321 2 JACK FOR E-BUS NETWORK ACCESS T7770C WALL MODULE 1 EARTH GROUND WIRE LENGTH SHOULD BE HELD TO A MINIMUM. USE THE HEAVIEST GAUGE WIRE AVAILABLE, UP TO 14 AWG (2. O MM2) WITH A MINIMUM OF 18 AWG (1. O MM2), FOR EARTH GROUND WIRE. TO ASSURE PROPER ELECTRICAL CONTACT, WIRES MUST BE TWISTED TOGETHER BEFORE INSERTION INTO THE TERMINAL BLOCK. SENSOR BYPASS SET PT LED E-BUS T7770C WALL MODULE 1 EARTH GROUND WIRE LENGTH SHOULD BE HELD TO A MINIMUM. USE THE HEAVIEST GAUGE WIRE AVAILABLE, UP TO 14 AWG (2. O MM2) WITH A MINIMUM OF 18 AWG (1. O MM2), FOR EARTH GROUND WIRE. [. . . ] The space temperature is below the frost alarm limit 42. 8F (6C) when the mode is FREEZE_PROTECT. The alarm condition remains until the temperature exceeds the alarm limit plus hysteresis. One of the Setpoints is not in the valid range or in the correct order. The air flow switch indicates that there is no air flow when the node is commanding the fan to run. [. . . ]