Honeywell W7761A - Manual (Page 8)

EXCEL 10 W7761A INPUT/OUTPUT DEVICE
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PWM - Pulse Width Modulated output; allows analog modulating control of equipment using a digital output on the controller.
RTD - Resistance Temperature Detector; refers to a type of temperature sensor whose resistance output changes according
to the temperature change of the sensing element.
RIO - Remote Input/Output Device. Provides auxiliary inputs and outputs for use with an Excel 10 Zone Manager and Excel
10 controllers.
Subnet - An E-Bus segment that is separated by a router from its Q7750A Zone Manager.
TOD - Time-Of-Day; the scheduling of Occupied and Unoccupied times of operation.
TPT - Twisted Pair Transceiver.
UV - Unit Ventilator Controller.
VA - Volt Amperes; a measure of electrical power output or consumption as applies to an ac device.
Vac - Voltage alternating current; ac voltage rather than dc voltage.
VAV - Variable Air Volume; Refers to either a type of air distribution system, or to the W7751 Excel 10 VAV Box Controller
that controls a single zone in a variable air volume delivery system.
VOC - Volatile Organic Compound; refers to a class of common pollutants sometimes found in buildings. Sources include
out-gassing of construction materials, production-line by-products, and general cleaning solvents. A VOC is
occasionally used as a measure of indoor air quality.
W7750 - The model number of the Excel 10 CVAHU Controllers (also see CVAHU).
W7751 - The model number of the Excel 10 VAV Box Controllers (also see VAV).
W7752 - The model number of the Excel 10 FCU Controllers (also see FCU).
W7753 - The model number of the Excel 10 UV Controllers (also see UV).
W7761 - The model number of the Excel 10 RIO Device (also see RIO).
Wall Module - The Excel 10 Space Temperature Sensor and other optional controller inputs are contained in the T7770 or
T7780 Wall Modules. See Application Step 5. Order Equipment for details on the various models of Wall Modules.
XBS - Excel Building Supervisor; a PC based tool for monitoring and changing parameters in C-Bus devices.
Construction
Controllers
The Excel 10 W7761A RIO Device is available in one model. It contains 4 resistive inputs that can be configured for either
20Kohm NTC or PT3000 sensors, 2 voltage or current inputs, 4 digital inputs and 8 Digital Outputs (Triacs) which may be
Discrete (maintained or momentary), Modulating (PWM) or Floating.
The W7761A consists of a single circuit board that is mounted in a sheet metal subbase and protected by a factory snap-on
cover. The device mounts with two screws (see Fig. 3 or 4). Using DIN rail adapters (see Fig. 5) they can also be snapped onto
standard EN 50 022 35 mm by 7.5 mm (1-3/8 in. by 5/16 in.) DIN rail. DIN rail is available through local suppliers. If using DIN
rail also purchase from Augat Inc. part number 2TK2D DIN rail (adapter) two each for every device (see Fig. 5). Wires are
attached to the screw terminal blocks on both sides of the device. Connection for operator access to the E-Bus is provided by
plugging the SLTA connector cable into the communications jack.
A channel in the cover allows the device status LED to be visible when the cover is in place. There are no field-serviceable
parts on the circuit board and, therefore, it is intended that the cover never be removed.
The W7761A can be mounted in any orientation. Ventilation openings were designed into the cover to allow proper heat
dissipation regardless of the mounting orientation. See Fig. 3 and 4.