Honeywell W7750A specifications Abbreviations and Definitions

EXCEL 10 W7750A,B,C CONSTANT VOLUME AHU CONTROLLER

Abbreviations and Definitions

AHU Air Handling Unit; the central fan system that includes the blower, heating equipment, cooling equipment, ventilation air equipment, and other related equipment.

CO Carbon Monoxide. Occasionally used as a measure of indoor air quality.

CO2 Carbon Dioxide. Often used as a measure of indoor air quality.

CARE Computer Aided Regulation Engineering; the PC based tool used to configure C-Bus and LONWORKS Bus devices.

C-BusHoneywell proprietary Control Bus for communications between EXCEL 5000 System controllers and components.

CPU Central Processing Unit; an EXCEL 5000 OPEN SYSTEM controller module.

cUL Underwriters Laboratories Canada

CVAHU Constant Volume AHU; refers to a type of air handler with a single-speed fan that provides a constant amount of supply air to the space it serves.

DDF Delta Degrees Fahrenheit.

D/X Direct Expansion; refers to a type of mechanical cooling where refrigerant is (expanded) to its cold state, within a heat-exchanging coil that is mounted in the air stream supplied to the conditioned space.

Echelon The company that developed the LONWORKS Bus and the Neuron chips used to communicate on the LONWORKS Bus.

Economizer Refers to the mixed-air dampers that regulate the quantity of outdoor air that enters the building. In cool outdoor conditions, fresh air can be used to supplement the mechanical cooling equipment. Because this action saves energy, the dampers are often referred to as economizer dampers.

EMI Electromagnetic Interference; electrical noise that can cause problems with communications signals.

E-LinkRefers to the Q7750A Zone Manager. This name is used in internal software and in CARE software.

EMS Energy Management System; refers to the controllers and algorithms responsible for calculating optimum operational parameters for maximum energy savings in the building.

EEPROM Electrically Erasable Programmable Read Only Memory; the variable storage area for saving user setpoint values and factory calibration information.

Enthalpy The energy content of air measured in BTUs per pound (KiloJoules per Kilogram).

EPROM Erasable Programmable Read Only Memory; the firmware that contains the control algorithms for the Excel 10 Controller.

Excel 10 Zone Manager A controller that is used to interface between the C-Bus and the LONWORKS Bus. The Excel 10 Zone Manager also has the functionality of an Excel 100 Controller, but has no physical I/O points.

NOTE: The Q7750A Zone Manager can be referred to as E-Link in the internal software, CARE.

E-VisionUser interface software used with devices that operate via the FTT LONWORKS Bus communications protocol.

Firmware Software stored in a nonvolatile memory medium such as an EPROM.

Floating Control Refers to Series 60 Modulating Control of a valve or damper. Floating Control utilizes one digital output to pulse the actuator open, and another digital output to pulse it closed.

FTT Free Topology Transceiver.

IAQ Indoor Air Quality. Refers to the quality of the air in the conditioned space, as it relates to occupant health and comfort.

I/O Input/Output; the physical sensors and actuators connected to a controller.

I x R I times R or current times resistance; refers to Ohms Law: V = I x R.

K Degrees Kelvin.

Level IV Refers to a classification of digital communication wire. Formerly known as UL Level IV, but not equivalent to Category IV cable. If there is any question about wire compatibility, use Honeywell-approved cables (see Step 5 Order Equipment section).

LONWORKS Bus Echelons LONWORKS network for communication among Excel 10 Controllers.

LONWORKS Bus Segment An LONWORKS Bus section containing no more than 60 Excel 10s. Two segments can be joined together using a router.

NEC National Electrical Code; the body of standards for safe field-wiring practices.

NEMA National Electrical Manufacturers Association; the standards developed by an organization of companies for safe field wiring practices.

Node A Communications Connection on a network; an Excel 10 Controller is one node on the LONWORKS Bus network.

NV Network Variable; an Excel 10 parameter that can be viewed or modified over the LONWORKS Bus network.

PC An Personal Computer with Pentium processor capable of running Microsoft Windows 95.

Pot Potentiometer. A variable resistance electronic component located on the T7770B,C or T7560A,B Wall Modules; used to allow user-adjusted setpoints to be input into the Excel 5000 or Excel 10 Controllers.

74-2958— 1 10