Unit installation

15
(Level 3 Priority
The following occupancy options are determined by the state of
Occupancy Schedule Number (Configuration→CCN→SCH.O
→SCH.N) and the Global Schedule Broadcast (Configuration
→CCN→ BROD→B.GS).
1. (Configuration→CCN→SCH.O→SCH.N = 0)
The unit is always considered occupied and the
programmed schedule is ignored. This is the factory
default.
2. (Configuration→CCN→SCH.O→SCH.N = 1-64)
Follow the local programmed schedule. Schedules 1 to 64
are local within the controller. The unit can only store one
local schedule and therefore changing this number only
changes the title of the schedule table.
3. (Configuration→CCN→SCH.O→SCH.N = 65-99)
Follow the global programmed schedule. If the unit is
configured as a Global Schedule Broadcaster
(Configuration→CCN→BROD→B.GS = YES), the unit
will follow the unit’s programmed schedule and broadcast
the schedule so that other devices programmed to follow
this schedule number can receive the schedule. If the unit is
not programmed as a Global Schedule Broadcaster
(Configuration→CCN→BROD→B.GS = NO), the unit
will receive broadcasted schedules from a unit programmed
to broadcast this schedule number. While using the
programmed schedule, occupancy can be temporarily
switched from unoccupied to occupied by pressing the
override button for approximately 3 seconds on the T--55,
T--56, T--58 or T--59 space temperature sensor. Override
will only occur if SPT Override Enabled (Configuration
→CCN→SCH.O→OV.SP) is set to YES. The length of the
override period when pressing the override button is
determined by the Override Time Limit (Configuration
→CCN→SCH.O→OV.TL). The hours remaining in
override is displayed as Timed Override Hours
(Configuration→CCN→SCH.O→OV.EX). This point can
also be changed from the local display or network to set or
change the override period length.
Indoor Fan Operation
The indoor fan is required for every function of the unit and has
several configurations that effect its operation. The Indoor Fan
Type configuration (Configuration →I.FAN →FTYP)setsthe
type of fan and how it is controlled. These 48/50LC units can
utilize the LEN VFD (FTYP = 1) or ECM (FTYP = 2) fan types.
The Number of Speeds configuration (Configuration →I.FAN
→ECM →NSPD) is used when Fan Type is set for ECM, and tells
the control how many speed outputs to use. The fan operation for
these two fan types is explained in detail below. For gas heating
units, the IGC fan request output (Inputs →GEN.I →IGC.F)is
also monitored by the MBB control. This can result in additional
modification of fan delays or other operation due to safety
functions of the IGC control. See the Gas Heating operation
section for more details. If configured for IAQ fan operation, the
fan may be turned on to satisfy air quality demands. See the Indoor
Air Quality section if using IAQ (indoor air quality) accessory
sensors. The fan can only run under thermostat or space sensor
control if the System Mode (SYS) status is enabled. The fan will
remain on if compressors or heat relays are ever stuck on. If
configured for fan status switch (FN.SW) and Shut Down on IDF
Failure is enabled (Configuration →UNIT →IDF.F =Yes),the
fan and unit will be shutdown without delay on alarm. Fan off
delays are honored when exiting specific HVAC modes. The
Fan-off Delay delays are as follows: Mech Cool (Configuration
→COOL →FOD.C), Elect Heat (Configuration →HEAT
→FOD.E), and Gas Heat (Configuration → HEAT →FOD.G).
Direct Drive Units (FTYP = ECM)
Direct Drive ECM fan units can operate with two or three speeds,
set by the number of fan speeds configuration point (NSPD). Low
Speed and High speed are standard unit speeds, and the Ventilation
Speed is the 3
rd
optional speed. These speeds are controlled by the
relays on the main base board (MBB). Indoor Fan Speed Relay 1
(Outputs →FANS →IDF1) controls the low speed command;
Indoor Fan Speed Relay 2 (Outputs →FANS →IDF2) controls
the high speed command; and Indoor Fan Speed Relay 3 (Outputs
→FANS →IDF3) controls the optional vent speed command. The
actual speeds are set by the motor tap in which they are wired to.
For only 2 speed units (NSPD = 2), the vent speed (IDF.3) will not
be used, instead the low speed output will be used during the
ventilation times. Refer to the heating or cooling operation sections
for details on when the fan changes speed, but general operation is
explained below.
Thermostat Control
In thermostat mode, the fan will run vent speed when only the fan
request G in ON. If a cooling request Y1 is ON the fan will be at
low speed. If the cooling request Y2 is ON the fan will be at high
speed. If a heating request W1 or W2 is ON, the fan will run high
speed. If the G call is dropped or was never on with an Y1, Y2,
W1, or W2 call; the fan will turn off after a configurable time delay
with respect to the HVAC mode that is ending.
Space Sensor Control
In Space Sensor mode, the fan will run vent speed if the unit is in
Occupied mode and the indoor fan is configured to always run
while occupied (Configuration →I.FAN →OC.FN = YES). If the
indoor fan is configured for intermittent fan (OC.FN = No), the fan
will only be on at low or high speed when there are cooling,
heating, or dehumidification running; or if there is an air quality
demand. In general, the fan will run low speed with part load
cooling and high speed any other time. During the unoccupied
period, the fan will operate intermittent. With intermittent fan, the
fan will turn off after a configurable time delay with respect to the
HVAC mode that is ending.
Belt Drive VFD Units (FTYP = LEN VFD)
Belt drive fan units are equipped with a Variable Frequency Drive
(VFD), which is powered direct from the distribution block and is
always on with power applied. The VFD communicates on the
Local Equipment Network (LEN) bus. When the thermostat or
space sensor control conditions require the fan, the control will
command the VFD to the desired speed with the Commanded Fan
Speed (Outputs →FANS →F.SPD) point. Feedback from the
VFD can be reviewed in the Supply Fan VFD Menu (Run Status
→S.VFD). Refer to the VFD Major Component section for more
information on the VFD (see page 54).
There are 5 speeds that the indoor fan will run at based on the
running mode and demand for conditioning. The five configurable
speeds are:
Supply Fan Maximum Speed (Configuration →I.FAN →FS.MX)
Supply Fan Speed 1 (Configuration →I.FAN →F.SP1)
Supply Fan Speed 2 (Configuration →I.FAN →F.SP2)
Supply Fan Speed 3 (Configuration →I.FAN →F.SP3)
Fan Speed – Ventilation (Configuration →I.FAN →FS.VN).
Fan speed is always calculated by evaluating the current applicable
conditions. Each fan speed “mode” is evaluated independently, and
the highest requested fan speed is used. When first ramping up
from 0%, the fan will run at max speed (FS.MX) for 1 minute.
Refer to the speed configurations below for an overview of usage;
refer to other specific operating sequences for more details on fan
operation during the corresponding mode.
Supply Fan Maximum Speed (FS.MX)
Max speed is the highest fan speed allowed. This is typically 100%
as pulleys are set to deliver design CFM to the space per job
requirement. Most safety conditions for the unit will override the
fan speed to this to help protect the unit. In free cooling after the
damper has been at max for 5 minutes, the fan will be set to max
before mechanical cooling can be used and locked at max while
damper is 100% and mechanical cooling is on. With a heating
demand, the fan will always run at this speed. When in an IAQ
override condition the fan will run at this speed. When the IAQ
48/50LC