Speedaire Operating Instructions & Parts Manual
Model 3Z411A
MAINTENANCE (Continued
c. Apply pressure with finger to
one belt at midpoint span.
Tension is correct if belt can
be depressed 3/8 to 1/2".
Make further adjustments
if necessary.
d. Check the alignment of
pulleys. Adjust if necessary.
e. Tighten mounting hardware
to secure motor on base.
f. Re-install guard and secure
with bolts.
Never operate
unit without belt guard in place.
Removal will expose rotating
parts which can cause injury or
equipment damage.
EVERY 90 DAYS OR 500
HOURS
1. Change crankcase oil. Use
type and grade oil as specified
in the section on "Compressor
Oil Specifications."
2. Check entire system for air
leakage around fittings,
connections, and gaskets,
using soap solution and brush.
3. Tighten nuts and capscrews
as required.
4. Check and clean compressor
valves, as required. Replace
parts when worn or damaged.
Valves must be
replaced in original position.
Valve gaskets should be re-
placed each time valves are
serviced.
4. Pull ring on all pressure relief
valves to assure proper
operation.
GENERAL MAINTENANCE
)
NOTES
BELTS
Drive belts must be kept tight
enough to prevent slipping. If
belts slip or squeak, see V-belt
maintenance in preceding
section.
tight, overload will be put on
motor and motor bearings.
COMPRESSOR VALVES
If compressor fails to pump air or
seems slow in filling up tank,
disconnect unit from power
source, remove valves, and clean
thoroughly, using compressed air
or a soft wire brush. After
cleaning, exceptional care must
be taken that all parts are
replaced in exactly the same
position and all joints must be
tight or the compressor will not
function properly. When all
valves are replaced and
connections tight, close hand
valve at tank outlet for final test.
Valve gaskets should be replaced
each time valves are removed
from pump.
NOTE: Do not disassemble
valves.
5
CENTRIFUGAL UNLOADER
AND PRESSURE RELEASE
VALVE
The centrifugal unloader is
operated by two governor
weights. It is totally enclosed and
lubricated from the crankcase of
the compressor. When
compressor starts the governor
weights automatically open
If belts are too
compressing the main spring,
allowing the unloader release
valve to close. When the
compressor stops, the main
spring returns the governor
weights to normal position
opening the pressure release
valve and unloading the
compressor.
This prevents overloading the
motor when starting. If air
continues to escape through the
governor or unloader pressure
release valve while operating,
this is an indication that the
release valve is not closing tightly
and may be held open by foreign
substance which has lodged on
the seat. In order to correct this,
remove the governor release
valve cap, giving access to release
valve spring and ball. Clean
thoroughly and return parts in
the same order in which they
were removed. Loose drive belts
can also cause unloader to leak
by preventing the compressor
from reaching proper speed.
(See "BELTS" above.)
THE INTERSTAGE PRESSURE
RELIEF VALVE
protect against interstage over
pressure and is factory set for
maximum pressure of 75 PSI.
3Z411A
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is provided to