York MA Section Iv Electric Heater Installation, Section V Low Voltage Control Connections

262675-UIM-A-0806

HORIZONTAL SUSPENSION

For suspension of these units in horizontal applications, it is recom- mended to use angle steel support brackets with threaded rods, sup- porting the units from the bottom, at the locations shown in Figure 4.

SUSPENSION SUPPORT LOCATIONS FOR HORIZONTAL APPLICATIONS
MIN. 3/8”
THREADED ROD
MIN. 1-1/2” x 1-1/2” Angle
Recommended length
26” minimum
with 2” clearance on
both sides of Air Handler
2			1-1/2
WW		YY
		XX
Units		Dimension
(Nominal Tons)	WW	XX	YY
1-1/2 - 3 Ton	16”	48”	22”
3-1/2 - 5 Ton	24”	53” - 58”	22”

SECTION IV: ELECTRIC HEATER INSTALLATION

If the air handler requires electric heat, install the electric heat kit according to the installation instructions included with the kit. After installing the kit, mark the air handler nameplate to designate the heater kit that was installed. If no heater is installed, mark the name plate appropriately to indicate that no heat kit is installed.

The HEAT ENABLE jumper (See Figure 5) must be moved to the HEAT position to enable operation of the heater.

Use only 4HK heater kits, as listed on Air Handler name plate and in these Instructions. Use data from Tables 11 through 18 for information on required minimum motor speed tap to be used for heating operation, maximum over-current protection device required and minimum electri- cal supply wiring size required for listed combination of Air Handler and Heater Kit.

For Upflow, Downflow and Horizontal right hand applications the kits can be installed without modification.

Field modification is required for Horizontal left-hand airflow application only. Follow instructions with heater for modification.

FIGURE 4: Typical Horizontal Installation

HEAT ENABLE	HUM OUT	EAC
	RELAY OUTPUT	RELAY OUTPUT
JUMPER

LOW FAN

RELAY OUTPUT

MODE JUMPER

HUM STAT JUMPER

FUSE

SPARE JUMPER

FIGURE 5: Control Board

SECTION V: LOW VOLTAGE CONTROL CONNECTIONS

The 24 volt power supply is provided by an internally wired low voltage transformer which is standard on all models, However, if the unit is con- nected to a 208 volt power supply, the low voltage transformer must be rewired to the 208 volt tap. See the unit wiring label.

Field supplied low voltage wiring can exit the unit on the top right hand corner or the right hand side panel. Refer to Figure 3.

Remove desired knockout and pierce foil faced insulation to allow wir- ing to pass through. Use as small of a hole as possible to minimize air leakage.

Install a 7/8” plastic bushing in the selected hole and keep low voltage wiring as short as possible inside the control box.

To further minimize air leakage, seal the wiring entry point at the outside of the unit.

The field wiring is to be connected at the screw terminals of the control board. Refer to Figures 10 & 11.

Unitary Products Group 5