Unit installation

8
Gas Heat (48LC)
Inspect the gas heat section of the unit. Verify the number of
burners match the number of heat exchanger openings and the
burner assembly is properly aligned. If the orifices were changed
out for elevation or Liquid Propane purposes, verify proper
installation. Visually inspect other components in heat section.
Verify gas pressures before turning on heat as follows:
1. Turn off field-supplied manual gas stop, located external to
unit.
2. Connect pressure gauge to supply gas tap, located on
field-supplied manual shutoff valve. (See Fig. 5.)
MANUAL SHUT OFF
(FIELD SUPPLIED)
PRESSURE TAP
(1/8˝ NPT PLUG)
GAS
SUPPLY
SEDIMENT TRAP
UNION
TO
UNIT
C09242
Fig. 5 -- Field Gas Piping
3. Connect pressure gauge to manifold pressure tap.
4. Turn on field-supplied manual gas stop. Enter Service Test
mode by setting Service Test→TEST to “ON” using the
Scrolling Marquee display. Temporarily install the jumper
wire between “R” and “W1” on TB. Use the Service Test
feature to set Service Test→HEAT→HT.1 to ON (first stage
of heat) using the Scrolling Marquee.
5. After the unit has run for several minutes, verify the supply
gas pressure is adequate per the base unit installation in-
structions. If not, adjust accordingly.
NOTE: Supply gas pressure must not exceed 13.0--in. wg.
6. Set Service Test→HEAT→HT.1 to OFF using Scrolling
Marquee.
7. Remove jumper wire if the unit will be operating under
thermostat mode. The jumper must remain if a space
temperature sensor (T-55, T-56, T-58, or System Pilot™
device) will control the unit.
8. Exit Service Test mode by setting Service Test→TEST to
“OFF” using the Scrolling Marquee.
CONTROLS QUICK SET--UP
The following information will provide a quick guide to setting up
and configuring the 48/50LC series units with ComfortLink
controls. Unit controls are pre-configured at the factory for
factory-installed options. Field-installed accessories will require
configuration at start-up. Service Test is recommended for initial
start--up. Additionally, specific job requirements may require
changes to default configuration values. See the CCN and Display
parameter tables and other sections of these instructions for more
details. Refer to the Major System Components or accessory
installation instructions for specific wiring detail.
Control Set Point and Configuration Log
During start up, accessory installation, and equipment service set
points and/or configuration changes might have to be made. When
setting set points or changing configuration settings,
documentation is recommend. The Control Log starting on page
78. should be filled out and left with the unit at all times, a copy
should also be provided to the equipment owner.
Thermostat Control
Wire accessory thermostat to the corresponding R, Y1, Y2, W1,
W2, and G terminals on the field connection terminal board located
at the unit control box.
The Unit Control Type configuration, Configuration
→UNIT→U.CTL, default value is for Thermostat (2) so there is
no need to configure this item.
The Thermostat Control Type, Configuration →UNIT→T.CTL,
selects the unit response to the thermostat inputs above.
NOTE: May not be compatible with heat anticipator thermostats.
Space Temperature Sensor Control -- Direct Wired
(T--55 or T--56 or T--59)
Wire accessory space temperature sensor(s) to the T-55 terminals
on the field connection terminal board located at the unit control
box. Refer to Field-Installed Accessories section for additional
information.
The Unit Control Type configuration, Configuration
→UNIT→U.CTL, must be set to Space Sensor (3). The jumper
wire in the installer’s packet must be connected between R and W1
on TB for heating mode to operate.
T--58 Communicating Room Sensor
Install the T-58 communicating thermostat. Connect the CCN
communication bus from the T-58 to the CCN terminals on the
field connection terminal board located at the unit control box.
Configure the unit’s CCN communication element number, bus
number, and baud rate. Configure the T--58’s CCN communication
bus number and baud rate the same as the unit, while the element
number has to be different. Configure the T--58 to send SPT to the
unit’s element number. Refer to the Field--Installed Accessories
section for additional information.
The Unit Control Type configuration, Configuration
→UNIT→U.CTL, must be set to Space Sensor (3). The jumper
wire in the installer’s packet must be connected between R and W1
on TB for heating mode to operate.
CCN Linkage Control
The CCN communication must be properly configured for the
48/50LC units and all other devices. Linkage configuration is
automatically done by the supervisory CCN Linkage device.
The Unit Control Type configuration, Configuration
→UNIT→U.CTL must be set to Space Sensor (3). The jumper
wire in the installer’s packet must be connected between R and W1
on TB for heating mode to operate.
Installation of an accessory supply air temperature (SAT) sensor in
the supply duct is recommended for Linkage applications. A
supply duct SAT measurement is valid for heating mode display,
while the factory-standard internal SAT is not valid for heating due
to its location upstream of the heating section. When installing the
supply duct SAT, the heating mode display is enabled by setting
Configuration→HEAT→SAT.H to ENBL.
Installation of an accessory return air temperature (RAT) sensor in
the return duct and wired to the space sensor input is recommended
for Linkage applications. This will allow the unit to continue to
run if Linkage communication is lost.
System Pilott -- Communication Space Sensor
Install the System Pilot and connect the CCN communication bus
from it to the unit’s CCN connection on the low voltage terminal
board. Configure the unit’s CCN communication element number,
bus number, and baud rate. Refer to the System Pilot’s installation
instructions for configuring it to be used as a space temperature and
attaching it to a unit.
Thermidistat Control
The thermidistat is a thermostat and humidistat combined
and the inputs are provided on the field connection terminal board. The
unit control type configuration, Configuration→UNIT→U.CTL,
default value is for thermostat (2) so there is no need to configure this
48/50LC