Donaldson Torit WSO 20, Installation And Operation Manual

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21
Donaldson Company, Inc.
Magnehelic
®
or Minihelic
®
Installation
(WSO 20 and 25-1)
The Magnehelic or Minihelic Gauge is used to measure
the pressure drop across the afterfilter.
1. Locate the Magnehelic or Minihelic knock-out in
the top left corner of the blower motor access door
(WSO 25-1) or cabinet (WSO 20).
2. Remove the diameter knockout from the door panel.
3. Install the Magnehelic or Minihelic gauge per the
Magnehelic or Minihelic installation sketch.
knockout
low pressure
high pressure
Afterfilter Magnehelic Gauge, WSO 25-1 shown
Remote-Mount Magnehelic Installation
The Magnehelic is a differential pressure gauge used
to measure the pressure difference between the clean-
and dirty-air plenums and provides a visual display of
filter change requirements. The high-pressure tap is
located in the dirty-air plenum and the low-pressure tap
is located in the clean-air plenum.
1. Choose a convenient, accessible location on or near
the unit for mounting that provides the best visual
advantage.
If unit is equipped with factory-installed pressure taps,
skip to Step 5.
Thoroughly clean any collected
coolants or material from the
collector prior to drilling to reduce the risk of
combustion. Failure to comply may result in
personal injury and/or property damage.
2. Before drilling, place a piece of non-combustible
cloth over the filter opening in the clean-air plenum
to protect them from drilling chips.
3. Place a piece of wood behind the drill location in the
dirty-air plenum to protect the filters from damage
by the drill bit. Use a .406-inch diameter bit to drill
the holes.
4. Mount the pressure tap hardware on the clean-air
plenum panel. Mount the pressure tap with the tee
inside the dirty-air plenum.
5. Plug the pressure ports on the back of the gauge
using two 1/8-in NPT pipe plugs supplied. Install two
1/8-in NPT male adapters supplied with the gauge
into the high- and low-pressure ports on the side of
the gauge. Attach the mounting bracket using three
#6-32 x 1/4-in screws supplied.
6. Mount the gauge and bracket assembly to the
supporting structure using two self-drilling screws.