Configurations, General, Fan type – Honeywell EXCEL 10 W7752D User Manual

Page 14

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EXCEL 10 FCU CONTROLLER LNS PLUG-INS USER GUIDE

EN2B-0285GE51 R0909

12

Configurations

General

The following sections provide an overview of the Excel 10

FCU Controller options related to inputs and outputs. See

Application Step 6. Plug-Ins Configuration Screens for

complete list of configuration options and defaults.

Table 7. Hardware options summary

option

possible configurations

fan type

• no

fan

• one-speed

• two-speed

• three-speed

fan interlock

• enabled

• disabled

FCU system type

• two-pipe

• four-pipe

output 1 actuator

type

• floating

• floating mid (one for heat/cool)

1

• one-stage

• two-stage

• three-stage

• PWM

• thermal

output 2 actuator

type

• floating

floating mid (one for heat/cool)

1

• one-stage

• two-stage

• three-stage

• PWM

• thermal

valve direction

• direct

• reverse

reheat

• none

• reheat (W7752D and F and

W7754P1000, only)

• free use (W7752D and F and

W7754P1000, only)

digital input

• not

used

• window

closed

• occupied

sensor

• air flow detector

• cool

changeover

• window

open

• unoccupied

sensor

• no air flow

• heat

changeover

• movement

• no

movement

wall module option

• local

• shared

temperature sensor

type

• none

• NTC

non-linearized

NOTE:

1

The floating-mid option is only for changeover applications

and uses only one of the two outputs.

Fan Type

Each fan coil unit controlled by an Excel 10 FCU Controller

can have a fan with up to three different speeds or no fan at

all. Multi-speed fans are switched at the same switching levels

as multi-staged heating control points (see Fig. 9). For

example, a three-speed fan will switch ON its first speed at

the same control level as the first stage of heating or cooling

up until the second stage of heating or cooling where the

second fan speed will switch on. A two stage fan will switch

with the first two stages of a 3-stage heating or cooling

system. Likewise, a single speed fan will turn ON at the first

stage of any multi-staged system. Conversely, a multi-speed

fan may follow multiple switching levels even for single-

staged, floating, PWM, or thermal actuator-based systems.


Hysteresis
The hysteresis for fan speed extends to the next lower

switching level (or a control level of 0) as is shown in Fig. 9.

For example, the second fan speed will remain ON until the

control level falls below the switching point for the first fan

speed. Minimum ON/OFF times can be configured and will

apply to all fan switching points.


Interlock
A fan interlock can be configured which prevents heating or

cooling outputs from being turned ON in the event of a fan

failure (where an air flow detector is installed to detect fan

failure). When fan interlock is configured, run-up and overrun-

times can be configured to delay switching ON the heating or

cooling equipment after switching ON the fan and delay

switching OFF the fan after the heating or cooling equipment

is switched OFF.

The fan can be configured to run continuously during the zero

energy band during occupied periods.

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