Quietpact 40G Diagnostic Repair Manual Model 4700 - Generac Parts

Section 7
DIAGNOSTIC TESTS
3. Insert the tachometer at end of the pinion gear and activate the
starter motor. A starter motor in good condition will be within the
following specifications:
STARTER MOTOR PERFORMANCE SPECIFICATIONS
AT 12 VOLTS DC:
MINIMUM MOTOR RPM = 800
MAXIMUM AMPS = 9
If the starter does not perform satisfactorily, it should
be replaced.
VOM
VICE
Black test lead
connected
to positive
battery terminal
12 VOLT
BATTERY
Red test lead
connected to
starter terminal
only for vapor withdrawal type systems. Vapor withdrawal
systems use the gas vapors that form above
the liquid fuel in the tank. Do NOT attempt to use the
generator with any liquid withdrawal type system.
Gas pressure delivered to the solenoid valve must be
properly regulated by means of a primary gas regulator.
Mount the primary regulator at the gas tank outlet
or in the supply line from the gas tank. The following
rules apply:
• For best results, the primary regulator supplies gaseous
fuel to the secondary regulator at 11 inches
water column. Do NOT exceed 14 inches water column.
• The installer must be sure the primary regulator is
rated at sufficient gas flow to operate the generator
plus all other gas appliances in the circuit.
REGULATOR
11 - 14" WATER COLUMN
PRIMARY
REGULATOR
TACHOMETER
STARTER
MOTOR
Negative battery
terminal
suitably grounded
Figure 7-21 – Starter Performance Test
Test 28 – Check Fuel Supply
DISCUSSION (Gasoline Models):
If the engine cranks but won’t start, don’t overlook the
obvious. The fuel supply may be low. Many RV generator
installations “share” the fuel tank with the vehicle
engine. When such is the case, the Installer may have
used a generator fuel pickup tube that is shorter than
the vehicle engine’s pickup tube. Thus, the generator
will run out of gas before the vehicle engine.
PROCEDURE:
Check fuel level in the supply tank. Attach a fresh fuel
supply if necessary and restart. Fuel may be stale,
causing a hard start.
RESULTS:
1. If necessary, replenish fuel supply.
2. If fuel is good, go to Test 29.
DISCUSSION (LPG Models):
LP gas is stored in pressure tanks as a liquid. The gas
systems used with these generators were designed
CARBURETOR
VAPOR
WITHDRAWAL
TANk
Figure 7-22 – Typical Propane Gas Fuel System
NOTE: Recommended MINIMUM gas flow rate for
all air-cooled QUIETPACT series generators is 67
cubic feet per hour.
If an existing primary gas regulator does not have
a sufficient flow capacity for the generator and
other gas appliances in the circuit, (a) install a primary
regulator with adequate flow rate, or (b)
install a separate regulator only and rated at least
67 cubic feet per hour. The inlet side of any primary
regulator that supplies the generator must connect
directly to a gas pressure tank. Do NOT tee
the generator line into a gas circuit feeding other
areas.
$
CAUTION!:
Use only approved components in
the fuel supply system. All components must
be properly installed in accordance with applicable
codes. Improper installation or use of
unauthorized components may result in fire
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