background image

FAN

RELAY

2ND

STAGE

HEAT

1ST

STAGE

HEAT

R

INDOOR HEAT PUMP UNIT

C

G

W1

Y1

W2

Y2

1ST STAGE

COMPRESSOR

2ND STAGE

COMPRESSOR

L1

L2

120

VAC

24

VAC

G

Y1

W1

Y2

W2

RH

RC

O

APRILAIRE MODEL

8870 THERMOSTAT

COMMUNICATION

TERMINALS

B

C

RSB

RSR

RSC

R

RSA

B+

A-

A+

B-

REF

REMOTE

SENSOR(S)

Y1

O

B

W1

C

1ST

STG

COMP.

REV

VALVE

COOL

REV

VALVE

HEAT

DEFROST

OUTDOOR HEAT PUMP UNIT

Y2

2ND
STG

COMP.

SEE
NOTE

IMPORTANT!

The thermostat B

terminal is for

reversing valve-heat.

DO NOT connect the

B terminal to common

side of transformer.

NOTE: HVAC installer may
need to connect 24V AC
to the R and C terminals to
check the HVAC operation.
If the automation system
is to be installed after the
HVAC installation, leave
the R and C terminals
connected to ensure the 
HVAC system operates. If
the automation system is
installed before the HVAC
wiring, then DO NOT connect  
HVAC wires to R and C.

24V FIELD WIRING

FACTORY WIRING

OPTIONAL 24V
FIELD WIRING (SEE NOTE)

21

DIAGRAM 6 – TWO STAGE HEAT PUMP

Summary of Contents for 8870

Page 1: ...tion Instructions MODEL 8870 These instructions are for connecting the Thermostat to the HVAC equipment To connect communication features please reference the Communicating Thermostat System Installation Manual ...

Page 2: ... s In The Box 3 3 Select The Thermostat Location 3 4 Disassembly 4 5 Mount Base To Wall 5 6 Setting The Dip Switches 6 7 Wiring The Thermostat 7 8 Reassemble The Thermostat 9 9 HVAC System Check Out 9 10 Optional HVAC Set Up Features 12 11 To Access The HVAC Set Up Features 13 Wiring Diagrams 16 22 Note Pages 23 25 Research Products Corporation 2001 ...

Page 3: ...t is not a 120 volt line voltage device 2 Improper installation may cause serious injury from electrical shock This product must be installed by a qualified heating and air conditioning contractor in accordance with NEC Standards and applicable local and state codes 3 Mercury is toxic and may be hazardous to health Any replaced thermostats containing mercury must be disposed of properly Contact lo...

Page 4: ...at type of heating system is will be installed in the house Then use Table 1 to determine if the proper numbers of wires are available depending on the HVAC System Additional wires will be required for communication system TABLE 1 APPLICATION OF HVAC WIRES DIAGRAM PAGE Single Stage Furnace AC 5 1 16 Two Stage Furnace Two Stage AC 7 2 17 Roof Top Unit Two Stage Heat Two Stage Cool 7 3 18 Boiler wit...

Page 5: ...e or with remote temperature sensors If the unit is stand alone there are certain measures that must be taken to ensure accurate temperature control STAND ALONE THERMOSTAT MOUNTING CRITERIA Mount on an interior wall In a room frequently occupied At least 18 inches from any outside wall Approximately 5 feet above the floor Check with local building codes for height requirements in commercial requir...

Page 6: ...delines for placement of the sensors and locate the thermostat indoors where operating range see specs will not be violated i e do not install in a cold garage or hot equipment room See the sensor installation literature for additional details 4 DISASSEMBLY No tools required use hands to pull the front panel off of the base Figure 2 While holding the base of the thermostat apply pressure to the ba...

Page 7: ...crew hole mounting locations leveling required for appearance only b If using supplied wall anchors drill 3 16 hole in the center of the marked locations and tap in the wall anchors If using the supplied screws only drill a 3 32 hole in the center of the marked locations c Fasten the base to the wall with the supplied screws d Seal wire entry using caulk drywall putty or insulation CAUTION Minimiz...

Page 8: ...the application needs Table 2 Figure 4 shows what each switch corresponds to depending on posi tion Switch one should be set in the OFF Servant position unless you plan to broadcast readings from remote temperature sensors to other thermostats in the system when there is no communication system in place FIGURE 4 ...

Page 9: ...ne Stage of Cooling Servant Fossil Multi H C 7 WIRING THE THERMOSTAT a Strip 1 4 of insulation from each wire to be used Figure 5 shows all wiring terminal definitions b Secure wires into the terminals on the base according to the appropriate wiring diagram Table 3 Use color coding practices i e white wire to W terminal whenever possible TABLE 3 APPLICATION DIAGRAM PAGE Single Stage Furnace AC 1 1...

Page 10: ...8 FIGURE 5 ...

Page 11: ...stat circuit board Installer must touch a grounded metal object before handling the circuit board 9 HVAC SYSTEM CHECK OUT HVAC installer may need to connect 24V AC to the R and C terminals to check HVAC operation If the automation system is to be installed after the HVAC installation leave the R and C terminals connected to ensure the HVAC system operates If the automation system is installed befo...

Page 12: ... MESSAGE DISPLAY MAIN DISPLAY REMOTE NETWORK OVERRIDE COOL HEAT EM AUX DEHUM HUMIDIFY BIAS DIF1 DIF2 C FAN RH ON ROOM F C F R O FIGURE 6 Use the Check Out Procedure Figure 7 on the next page to determine if the thermostat is controlling the HVAC equipment ...

Page 13: ...nd the COOL icon begins to flash If there is a second stage it will begin in 4 minutes 7 6 MODE Press the Mode button until HEAT appears along with the current heat setting Use the up arrow to raise the set point 3 F above room temp In 5 10 seconds the first stage of heating begins and the HEAT begins to flash If there is a second stage it will begin in 4 minutes 1 5 Press the Mode button until OF...

Page 14: ...ll rise for the cooling heating to stop For example if the temperature setting was 70 F and the 1st stage differential was set at 0 5 F in the heat mode the heat would come on at 69 5 F and stay until the temperature was 70 5 F A small differential will result in a tighter control but more heating cooling cycles 3 2ND STAGE DIFFERENTIAL again adjustable between 0 5 F and 2 0 F this also determines...

Page 15: ... buttons will display the settings 4 SHOW DATE AND TIME the message display will by default scroll three messages showing the status of the mode fan and equipment outputs A fourth date and time can be added to this list However the automation system must transmit the time and date to the thermostat at least once a day If the automation system is not capable of doing this the date and time can be c...

Page 16: ...ing Sub Menu Figure 8 also shows the Temperature Set Up Balance Points Set Up and Display Set Up sub menus expanded The Scroll Up and Scroll Down buttons are used to move between menu items or change values The Enter button is used to select a menu item or enter a value When in Thermostat Set Up if none of the three navigation buttons are pressed in 5 min utes the display will return to Passive Di...

Page 17: ...15 FIGURE 8 Cont ...

Page 18: ...ted to ensure the HVAC system operates If the automation system is installed before the HVAC wiring then DO NOT connect HVAC wires to R and C FAN RELAY 1ST STAGE HEAT R ONE STAGE FURNACE C G W1 Y1 1ST STAGE COOL 120 VAC 24 VAC 1ST STG COOL ONE STAGE AIR CONDITIONER Y1 C G Y1 W1 Y2 W2 RH RC O APRILAIRE MODEL 8870 THERMOSTAT B C RSB RSR RSC R RSA B A A B REF SEE NOTE 24V FIELD WIRING FACTORY WIRING ...

Page 19: ...STAT COMMUNICATION TERMINALS B C RSB RSR RSC R RSA B A A B REF REMOTE SENSOR S NOTE HVAC installer may need to connect 24V AC to the R and C terminals to check the HVAC operation If the automation system is to be installed after the HVAC installation leave the R and C terminals connected to ensure the HVAC system operates If the automation system is installed before the HVAC wiring then DO NOT con...

Page 20: ...RSR RSC R RSA B A A B REF REMOTE SENSOR S NOTE HVAC installer may need to connect 24V AC to the R and C terminals to check the HVAC operation If the automation system is to be installed after the HVAC installation leave the R and C terminals connected to ensure the HVAC system operates If the automation system is installed before the HVAC wiring then DO NOT connect HVAC wires to R and C SEE NOTE 2...

Page 21: ...ller may need to connect 24V AC to the R and C terminals to check the HVAC operation If the Automation system is to be installed after the HVAC installation leave the R and C terminals connected to ensure the HVAC system operates If the automation system is installed before the HVAC wiring then DO NOT connect HVAC wires to R and C 1ST STG COOL AIR CONDITIONER Y1 C 1ST STG HEAT W1 C 120 VAC 24 VAC ...

Page 22: ...E HVAC installer may need to connect 24V AC to the R and C terminals to check the HVAC operation If the automation system is to be installed after the HVAC installation leave the R and C terminals connected to ensure the HVAC system operates If the automation system is installed before the HVAC wiring then DO NOT connect HVAC wires to R and C Y1 O B W1 C 1ST STG COMP REV VALVE COOL REV VALVE HEAT ...

Page 23: ... NOTE IMPORTANT The thermostat B terminal is for reversing valve heat DO NOT connect the B terminal to common side of transformer NOTE HVAC installer may need to connect 24V AC to the R and C terminals to check the HVAC operation If the automation system is to be installed after the HVAC installation leave the R and C terminals connected to ensure the HVAC system operates If the automation system ...

Page 24: ... DO NOT connect the B terminal to common side of transformer NOTE HVAC installer may need to connect 24V AC to the R and C terminals to check the HVAC operation If the Automation system is to be installed after the HVAC installation leave the R and C terminals connected to ensure the HVAC system operates If the automation system is installed before the HVAC wiring then DO NOT connect HVAC wires to...

Page 25: ...23 NOTES ...

Page 26: ...24 NOTES ...

Page 27: ...25 NOTES ...

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