- 38 -
VENT PIPE INSTALLATION
Note
: Maximum number of M
90
is 3pcs.
Maximum number of M
45
is 5pcs.
In case of combination use for M
90
and M
45
, maximum total number is 5pcs.
To prevent the vent/air intake piping from occurring condensation, the fan has following 4 type
settings with 2 dip swiches, No.7 & No.8 in each D value.
Both dip switch No.7 & No.8 ON is factory setting ; this is suitable for over 30 in D value.
• Depending upon the vent length, dip switch No.7 & No.8 on PCB may need to be adjusted to
compensate fan speed. Read the following instructions to determine which position this switch
should be placed in.
• In case D value is 30 and above, leave dip switch No.7 & No.8 (ON).
• In case D value is 21 and above, but less than 30, set dip switch No.7 OFF and leave dip switch
No.8 (ON).
• In case D value is 15 and above, but less than 21, leave dip switch No.7 (ON) and set dip switch
No.8 OFF.
• In case D value is less than 15, set both dip switch No.7 & No.8 OFF.
(Factory setting No.7 & No.8 ON.)
< Dip switch on PCB >
12
34
5
6
7
8
OFF
• In case extension of the vent pipe is required, it shall be limited to the maximum of 41' (12.5m)
based on the formula below.
However, the maximum height of the vent pipe is limited to 23 feet.
• Calculate D (distance) value according to the length of the vent pipe and the number of elbows.
D = L + (M
90
X 6) + (M
45
X 1.5)
D : Distance
L : Total extended length of straight vent pipe and adjustable vent pipe.
M
90
: Number of 90º elbow
M
45
: Number of 45º elbow
< Dip switch on PCB >
12
34
5
6
7
8
OFF
< Dip switch on PCB >
12
34
5
6
7
8
OFF
• Example #1 :
• Example #2 :
Maximum height 23' (7m)
Drain tee
90º elbow
Rain cap
Air intake pipe
No less than 2º
(1/4 in/ft) upward
Roof
flashing
L termination
Reducer
In case of 6 straight vents and 2-90º elbows.
(Refer to Fig. 7 right drawing. page 50)
D = 18' + (2x6) + (0x1.5) = 30
In case of L termination and reducer.
(Refer to Fig. 4-1 page 45)
D = 0' + (0x6) + (0x1.5) = 0
No.1 dip switch is
ON with Natural
Gas and OFF with
Propane Gas.
*
Summary of Contents for MWH-180
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Page 61: ... 59 WIRING DIAGRAM ...