GENERAL
The Plus One system was designed to combine warm air
furnaces (indoor units) with heat pumps for maximum
comfort and energy efficiency during the entire year.
This is compatible only with furnaces having 24V trans-
formers at least 35 VA.
The control center enclosure is made of galvanized steel, with
an attractive decorative logo on the front panel.
This enclosure is 9-3/16" x 7-1/8" x 2-1/2" in size. When the
cover is removed, the components are readily accessible for
field hook-up or service. All field electrical connections are to
terminal board, or wire nuts (field supplied). This assembly
can be mounted in any position.
INSPECTION
1. Unpack the Plus One Control Center and remove cover.
Included inside are:
Control Box Assembly
Installer’s Guide
2. Check for any shipping damage, and if any, report it to
the carrier immediately.
3. The field electrical connections and wiring must be done
in accordance with the “National Electrical Code” and
must comply with local electrical codes.
4. Minimum gauge 18 AWG thermostat wire.
SYSTEM USAGE AND INSTALLATION
This system uses a heat pump outdoor section with an
indoor heat pump coil, a Plus One Control Center and warm
air furnace.
The Plus One Control Center as shipped from the factory is
for operation in the “non-restrictive” mode. For “restrictive”
operation, field wire in accordance with appropriate diagram
(included in these instructions). TAYSTAT250A is required.
1. The indoor coil must be installed on the supply side of
the furnace.
2. The Plus One Control Center is installed in close proxim-
ity to the furnace.
3. The outdoor thermostat (when used in restricted opera-
tion only) is installed in the outdoor section in accor-
dance with TAYSTAT250A installation requirements.
Add-on Heat Pump Kit
TAYPLUS103A
Installer’s Guide
For Load Shedding in the heating cycle, use the restricted
hook up diagram. The utility company’s load shedding relay
will be wired in place of the ODT as shown. The utility
company’s relay must be a SPDT switch type.
Do not connect wires to W terminal at thermostat and
terminal #1 at ODT if utility company requires lockout
(restriction) of gas furnace at an outdoor temperature above
the setting on the outdoor thermostat. Emergency heat cycle
and furnace blower will come on if thermostat is switched to
emergency heat.
INSTALLATION OF BONNET THERMOSTAT
*THT1248 ON ALL OIL FURNACES
“A” Coil Application (Upflow)
1. Remove front cover panel from the “A” coil enclosure.
2. Select a location to make a 1-1/2" hole for the bonnet
thermostat to pass thru (see Figure 2) in front coil baffle
of “A” coil.
3. The location of the 1-1/2" hole should be on a vertical line
(plane) to the top of the “A” coil and approximately 4" - 6"
down from the front end of coil.
4. With the template provided make a 1-1/2" hole in coil
baffle, install the bonnet thermostat with the screws
provided in the kit.
5. Drill 3/8" hole in front cover panel for field wiring and
install grommet provided with this kit.
6. Connect bonnet thermostat leads in Plus One Control
Center thru grommet. (See hookup diagram).
7. Replace front cover panel on “A” coil enclosure and
secure.
“A” Coil Application (Downflow)
1. Select a location on air entering side of the coil enclosure
to make a 1-1/2" hole for the bonnet thermostat to pass
thru (see Figure 1).
2. The location of the 1-1/2" hole should be on a horizontal
line (plane) to the top of the “A” coil. The thermostat can
not be in contact (touching) the coil.
3. With template provided, make a 1-1/2" hole in the coil
enclosure, install the bonnet thermostat with the screws
provided.
*Available thru Service Parts only.
ALL phases of this installation must comply with NATIONAL, STATE AND LOCAL CODES
IMPORTANT —
This Document is
customer property
and is to remain with this unit. Please return to service information
pack upon completion of work.
PLUS-IN-1C
18-BH15D7-4
