Engine Adjustment
There are regional variances in the composition of natural
gas. Each HSG unit is adjusted at the factory for NG
operation. If the generator output voltage or frequency
measured during initial Start-Up (paragraph #9 on page 13)
is outside the listed ranges, the combustibility of the gas
supplied at the installation site may be substantially different.
To adjust the engine for this difference, proceed as follows.
1.
Remove the Air Intake access door.
2.
Remove the three M5 sheet metal screws that hold
the control panel wiring cover to the air intake guard
(Figure 13).
Figure 13 — Accessing Engine Mixture Control
3.
Remove the six (M5) sheet metal screws that hold the
air intake guard to the engine fan panel.
4.
An access hole is visible above the engine fan panel
(see Figure 13). It will be covered with a plug. Remove
the plug to gain access to the adjustment screw.
NOTE: The mixture adjustment screw is the brass slotted
screw in the center of the aluminum boss directly visible in
the access hole.
5.
Connect an accurate frequency meter to the load side
of the main circuit breaker (on the back of the control
panel).
6.
Ensure that the 15 Amp fuse is installed.
7.
Set the generator's main circuit breaker ON.
8.
Set the AUTO/OFF/MANUAL switch to MANUAL.
When the engine starts, allow it to warm up for two
minutes.
Briggs & Stratton Power Products Home Generator
Installation Manual
Remove
Access
Hole Plug
14
9.
When the engine speed has stabilized, slowly rotate
the adjustment screw clockwise and/or
counterclockwise until the maximum (peak) frequency
is reached. Normal no load frequency is 62.0 to
62.5 Hz.
10. Turn the service disconnect to the transfer switch off.
The transfer switch will connect to the generator after
a short time delay.
11. Load generator to rated Natural Gas rating.
12. Connect an accurate frequency meter to the load side
of the main circuit breaker (on the back of the control
panel). Frequency should be above 57.0 Hz.
13. If frequency is below 57.0 Hz, slowly rotate the
adjustment screw clockwise and/or counterclockwise
until frequency is above 57.0 Hz. Reinstall the access
hole plug.
14. Turn the service disconnect to the transfer switch on.
The transfer switch will connect to the utility after a
short time delay.
15. Set the AUTO/OFF/MANUAL switch to OFF.
16. After the engine has stopped running, reinstall the air
intake guard.
17. Reinstall the control panel wiring cover to the air
intake guard.
18. Reinstall the air intake access panel.
19. Set the AUTO/OFF/MANUAL switch to AUTO.
AUTOMATIC OPERATION
SEQUENCE
The generator's control panel houses a logic control circuit
board.This control board constantly monitors utility power
source voltage. Should that voltage drop below a preset
level, control board action will signal the engine to crank
and start.
When utility source voltage is restored above a preset
voltage level, the engine is signaled to shut down.
The actual system operation is not adjustable and is
sequenced by sensors and timers on the control board, as
follows: