Valley Comfort Systems MP80, Installation And Operation Manual

MP80.PUB  Version 1.07                                              21                        

ADD-ON TO OIL FURNACE 

The MP80 may be connected to an oil furnace having a rated input of up to 1.2 USGPH.  Minimum blower 
capacity must be at least 900 cfm..  A regular upflow oil furnace may be used and connected as per fig. 1on 
page 15.  The MP80 can be located on either side of the oil furnace.  Minimum interconnect duct size is 12" X 
18" with minimum 6" inside radius elbows   The wood furnace requires a chimney approved for solid fuel use.  
Maintain clearances to all combustibles.  Refer to general instructions portions of this manual also. 
If changes are made to the installation of the oil furnace these shall comply with CSA Standard B139. 
 
An interconnect limit switch system must be included in the control circuitry to prevent the simultaneous 
operation of both furnaces when the hot air plenum reaches the preset level of 150°F.  See Typical wiring 
Diagram 6 on pg. 22.

ADD-ON TO GAS FURNACE 

The MP80 may be connected to a gas furnace having a rated input up to 120,000 BTU.  Minimum blower 
capacity must be at least 900 cfm..  A counterflow gas furnace may be used with an interconnect duct as 
indicated in Fig 1. page 15.  A regular upflow gas furnace may also be used and connected as per Fig 1on pg. 
22.  The MP80 can be located on either side of the gas furnace.  Minimum interconnect duct size is 12" x 18" 
with minimum 6" inside radius elbows.  The wood furnace requires a chimney approved for solid fuel use.  
Maintain clearances to all combustibles. Refer to general instructions portions of this manual also.  
THE OPERATION OF THE GAS FURNACE MUST BE VERIFIED, FOR ACCEPTABLE OPERATION 
BEFORE AND AFTER INSTALLATION OF THE ADD ON, BY A GAS FITTER WHO IS RECOGNIZED 
BY THE REGULATORY AUTHORITY.  DO NOT CONNECT TO ANY FURNACE THAT HAS NOT 
BEEN CERTIFIED INITIALLY AS COMPLYING WITH CGA STANDARD CAN1-2.3 OR ITS 
PRECEDENTS.  DO NOT CONNECT TO ANY FURNACE THAT IS NOT EQUIPPED WITH AN AIR 
CIRCULATION BLOWER. 
DO NOT, UNDER ANY CIRCUMSTANCES, CONNECT THE MP80 TO A CHIMNEY WHICH ALSO 
VENTS A GAS FURNACE OR OTHER GAS APPLIANCE. 
 

ADD-ON TO ELECTRIC FURNACE 

The MP80 may be added to an electric furnace with heating capacity between 10KW and 25 KW.  Minimum 
blower capacity must be at least 900 cfm.  Electric furnaces approved for installation in any position can be 
inverted and used in a down flow position using an adapter duct between the furnace and the add-on as 
indicated in fig. 1 pg. 13.  The electric furnace can be located on either side of the MP80 but clearances to 
combustibles must be maintained. Refer to general and pressure loss instruction portions of this manual. (pg. 
15)  
If changes are made to the installation of the electric furnace they must comply with CSA Standard C22.1. 
An interconnect limit switch system must be included in the control circuitry that prevents the simultaneous 
operation of both furnaces when the hot air plenum reaches the preset level of 150°F.  Typical wiring diagram 
follows below re: Diagram 8A (with W1,R,C and G connections.) and 6 for basic units. 
 

An interconnect limit switch system must be included in the control circuitry to prevent the 
simultaneous operation of both furnaces when the hot air plenum reaches the preset level of 150°F.  
Typical wiring diagram follows, see Diagram 6 on pg. 20