Wire Requirements

Figure 1 and the table show the number of wires that must be available at the thermostat in stand-alone thermostat systems (i.e. not as part of an Aprilaire® Model 6504 Intelligent Zoned Comfort System). Figure 1 shows optional connections to both an outdoor temperature sensor and an Aprilaire® Automatic Digital Humidifier Control (ADHC), but only one or the other is necessary. All wire is standard 18-24 gauge thermostat cable.

(1) SELECT A MOUNTING LOCATION

If installing the thermostat alone…

• Mount on an interior wall, in a frequently occupied space.

• Keep the thermostat 18" from an outside wall.

• Mount the thermostat approximately 5 feet above the floor.

If installing an indoor temperature sensor…

• Mount the thermostat where it can be readily accessed.

Note that the backlighting illuminates whenever a button

is pressed.

Figure 1 – Thermostat Wire
	OPTIONAL –
	AUTOMATIC	HVAC
DIGITAL HUMIDIFIER		HVAC
DIGITAL HUMIDIFIER		EQUIPMENT
	CONTROL	EQUIPMENT
	CONTROL
	(ADHC)
OPTIONAL –	2-WIRES	SEE	OPTIONAL –
OPTIONAL –	2-WIRES	TABLE	INDOOR
OUTDOOR		TABLE	INDOOR
TEMPERATURE			TEMPERATURE
SENSOR			SENSOR
2-WIRES	MODEL 8570		2-WIRES
	MODEL 8570
	THERMOSTAT

Application	# Wires	Diagram (Page)
Single-Stage Furnace/AC	5	1 (9)
Two-Stage Furnace/AC	7	2 (10)
Two-Stage Roof Top Unit	7	3 (11)
Boiler w/AC (2-transformer)	6	4 (12)
Radiant 1st Stage Heat,	6	5 (13)
Furnace 2nd Stage and AC
Single-Stage Heat Pump	6	6 (14)
Single-Stage Heat Pump	7	7 (15)
w/Two Stages Aux. Heat
Two-Stage Heat Pump	8	8 (16)

Height requirements are different for compliance with the

Americans with Disabilities Act (ADA) – 48" maximum height

for forward reach and 54" maximum height for side reach.

• Thermostat can be mounted to a vertical junction box (j-box).

• DO NOT mount the thermostat:

– behind doors, in corners or other dead air spaces.

– in direct sunlight or near lamps, appliances or other

sources of heat.

– on an outside wall or wall exposed to an unconditioned

space (i.e. garage).

– in the flow path of a supply register, in stairways or near

outside doors.

– on a wall where concealed pipes or ductwork could

• Thermostat can be mounted on a vertical junction box (j-box).

• DO NOT mount the thermostat where the operating range

temperatures will be exceeded (i.e. attic or unventilated

equipment room).

• Mount the sensor in the same location as if installing a

thermostat alone.

When this thermostat is connected to a Model 6504 as shown in Figure 2, only one four-wire cable need be run from the thermostat to the Model 6504. Use standard 18-24 gauge thermostat cable.

Figure 2 –

Model 6504

Wire

MODEL 8570

THERMOSTAT

4-WIRES

MODEL 6504

influence the sensor.

– near sources of electrical interference such as arcing

switch contacts.

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