Modine Manufacturing PD/BD Installation Instructions Manual

For Units being Converted from Natural Gas 

to Propane Gas Concurrently

Follow carefully the propane conversion instructions, found 

in Bulletin 75-511, using the proper high altitude main burner 

orifices called out in this literature (75-535) 

instead of 

the 

orifices in propane conversion kit.

SELECTION OF THE PROPER KIT

To select the proper high altitude kit you need to know the 

specifics of the heater you will be converting, and the altitude 

it will be going into. If the high altitude kits are ordered at the 

same time as the unit heater, all pertinent information relative to 

the heater can be obtained from the catalog. If the high altitude 

kit is needed after the unit heater is in the field, you need to 

refer to the carton label or unit heater serial plate to obtain the 

necessary information. Figure 8.2 shows a portion of the unit 

heater serial plate where this information may be obtained. 

Referring to this figure, the prefix letters and successive 

numbers which are needed for kit selection are BV 100. The 

letters identify the model and the numbers the size of the unit. 

To determine the type of gas the unit is designed for, see the 

gas designation disc (Figure 1.1) and the type of gas, located on 

the serial plate.

After obtaining this information, refer to the proper selection 

chart. The selection charts are differentiated by product type, 

altitude and fuel type. 

Remember, if you are converting from 

natural gas to propane gas and want to operate at high altitude, 

both a propane conversion kit and a propane high altitude kit 

must be used.

 Selection charts include the proper kit suffix, the 

orifice drill size, and the number of orifices required for the unit 

being converted. Drill sizes are also stamped on each orifice.

HIGH ALTITUDE CONVERSION 

For Existing Natural or Propane Gas Units

Gas-fired equipment ratings are certified by C.S.A. For 

elevations above 2000 ft., ANSI Z223.1 requires ratings be 

reduced 4 percent for each 1000 ft. above sea level. C.G.A. 

requires that ratings be reduced 10% at elevations above 2000 

ft. 

To accommodate higher altitude operation, equipment 

must be converted by changing orifices as explained in 

this instruction sheet. 

Tables 2.1 thru 5.2 list orifice kits which 

comply with both ANSI Z223.1 recommendations and C.S.A. 

requirements.

Table of Contents

 Pages

High altitude conversion ......................................................... 1

High altitude propane gas

conversion from natural gas ............................................. 1

Selection of the proper kit ....................................................... 1

Installation of kits .................................................................... 6

Cross reference ...................................................................... 8

THIS MANUAL IS THE PROPERTY OF THE OWNER. 

PLEASE BE SURE TO LEAVE IT WITH HIM WHEN YOU LEAVE THE JOB.

SELECTION AND INSTALLATION INSTRUCTIONS

high altitude orifice kit

models PD/BD, PDP/BDP, PSH/BSH

and model series “D”, “H”, “I”, “O”  duct furnace/make up air units

(not  including separated combustion) 

Figure 1.1 - Gas Designation Disc

EQUIPPED

FOR USE

WITH

PROPANE

GAS

NTRL

5H604841A

NRTL

IMPORTANT

Conversion from natural gas to propane gas 

is allowed

 for 

PD/BD, PDP/BDP, and PSH/BSH models with 11,12, 30, 

or 31 control codes, built in January, 1987 or later. 

For this 

conversion, both a propane conversion kit and a propane 

high altitude kit must be used.

WARNING

1.  All field gas piping must be pressure/leak tested prior to 

operation. Never use an open flame. Use a soap solution 

or equivalent for testing.

2.  Gas supply shall be shut-off and the electrical power 

disconnected before proceeding with the conversion. 

Failure to do so could result in fi re, explosion or electrical 

shock.

1.  The use of this manual is specifically intended for a 

qualified installation and service agency. All installation 

and service of these kits must be performed by a qualified 

installation and service agency.

2.  These instructions must also be used in conjunction with 

the Installation and Service manual originally shipped with 

the appliance being converted, in addition to any other 

accompanying component supplier literature.

IMPORTANT

As Modine Manufacturing Company has a continuous 

product improvement program, it reserves the right 

to change design and specifications without notice.

75-535.11

5H605846A Rev. U

l

December, 2008