3
ATH15-501.0 (
Supplement to ATH15-500.10
)
GAS HEAT OPTION MODEL IDENTIFICATION
Gas Heating Option Identification
These instructions are supplemental to those in the main
Installation and Service Manual, literature #ATH15-500.10.
These supplemental instructions are only used for units that
meet the following conditions:
•
Digit 17 of the MPR unit model number (not the gas heat
option model number) is 2, 3, 5, or 6 indicating the gas
heat option. Example:
MPR20CD1A1A8S16D
2
KHDNNNN (Digit 17=2)
•
Digit 11 of the gas heat option furnace model number (not
the model MPR unit model number) is 6, 9, A, B, C, OR D.
Example:
FMP0600SSN
9
H0A (Digit 11=9)
Refer to the Installation and Service Manual, Literature
#ATH15-500.10 for full model nomenclature descriptions.
Identify the Gas Control Type
Before you begin, review the furnace serial plate to determine
the model installed. The serial plate is located on the right
hand access door for the furnace section. A sample is shown in
Figure 3.1. Note that the furnace serial plate is separate from
the unit (model MPR) serial plate.
Digit 11 of the furnace model number denotes the type of gas
control used. These are defined below:
For B-Cabinet (MPR Model Digit 6) Units Only:
The unit includes one heat exchanger with control as follows,
indicated by Digit 11:
6
- A single manifold with Beckett advanced modulation
control which varies the manifold pressure and power
exhauster speed based on demand. High turn down and
more consistent efficiency are possible with this control.
B
- A split manifold equipped with Beckett advanced
modulation control on part of the manifold which varies
the manifold pressure and fixed input on the rest of the
manifold. This system varies power exhauster speed
based on input. Highest possible turn down and more
consistent efficiency are possible with this control.
For C and D-Cabinet with rating of 800MBH and lower:
The unit includes two heat exchangers with control as follows,
indicated by Digit 11:
9
- One heat exchanger equipped with a single manifold
with advanced Beckett modulation control and the other
equipped with two stage control. The second heat
exchanger is controlled by the Carel controller and will
switch from high and low input and off based on demand.
C
- One heat exchanger equipped with a split manifold
with advanced Beckett modulation control and the other
equipped with two stage control. The second heat
exchanger is controlled by the Carel controller and will
switch from high and low and off based on demand.
For D-Cabinet with rating of 900MBH and higher:
The unit includes four heat exchangers with control as follows,
indicated by Digit 11:
A
- One heat exchanger equipped with advanced Beckett
modulation control and the others equipped with single
stage control. Those heat exchangers are controlled by
the Carel controller and will and turn on and off based on
demand.
D
- One heat exchanger equipped with a split manifold
with advanced Beckett modulation control and the
others equipped with single stage control. Those heat
exchangers are controlled by the Carel controller and will
turn on and off based on demand.
Refer to the following flowchart to determine next steps:
THIS SECTION APPLIES TO ONLY CERTAIN
UNITS WITH OPTIONAL GAS HEAT
(MPR MODEL DIGIT 17=2, 3, 5 OR 6). REVIEW
THE SECTION BELOW TO DETERMINE IF
THESE INSTRUCTIONS ARE APPLICABLE.
REVIEW BEFORE PROCEEDING
Figure 3.1
Serial Plate Example (D-Cabinet Heat Option Shown)
IS THE FURNACE MODEL
DIGIT 11 = 6, 9, A, B, C, OR D?
DO NOT USE THESE INSTRUCTIONS.
RETURN TO THE INSTALLATION AND
SERVICE MANUAL, LITERATURE
#ATH15-500.10 FOR INSTRUCTIONS.
PROCEED TO THE
NEXT PAGE FOR
INSTRUCTIONS.
YES
NO
