Generac®Power Systems, Inc. 19
Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
4.7 SCHEDULED MAINTENANCE
The following is a recommended maintenance schedule for Generac Guardian small standby and residential gen-
erator sets. The established intervals in the schedule are the maximum recommended when the unit is used in an
average service application. They will need to be decreased (performed more frequently) if the unit is used in a
severe application. Use the unit hour meter or calendar time, whichever occurs first, from the previous mainte-
nance interval to determine the next required maintenance interval.

Service Maintenance Interval Information:

The various service maintenance intervals are designated by interval numbers as follows:
1An early inspection of the generator set to insure it is ready to operate when required and to identify any poten-
tial problem areas.
Performed monthly or following each 10 hours of operation of the unit and requires approximately .5 man-
hours per unit to complete.
This inspection may be performed by the end user providing the following safety steps are taken to prevent
the engine from starting automatically without warning:
To prevent injury,perform the following steps in the order indicated before starting any maintenance:
• Disable the generator set from starting and/or connecting to the load by setting the control panel
AUTO-OFF-MANUALswitch to the OFF position.
• Remove the control panel fuse.
• Turn off utility supply to engine water heater.
• Turn off the battery charger by turning off utility supply to the transfer switch.
• Remove the negative battery cable.

The battery charger must be turned off BEFORE removing the battery cable to prevent an over current condi-

tion from burning out sensitive control panel components and circuits.

Following all maintenance, reverse these steps to insure the unit is returned to standby setup for normal
operation when required.
2A break-in service inspection of the generator set to insure it is ready to operate and carry the load when
required, and to identify any potential problem areas.
Performed ONLY ONCE following the first three months or the first 30 hours of operation after purchase of
the unit and requires approximately 2.5 man-hours per unit to complete.
This inspection contains some maintenance tasks which require special tools, equipment, and/or knowledge
to accomplish and should be performed only by an authorized Generac Service Dealer.
3An operational inspection of the generator set to insure it is ready to operate and carry the load when required,
and to identify any potential problem areas.
Performed semi-annually or following each 50 hours of operation of the unit and requires approximately 1.5
man-hours per unit to complete.
This inspection contains some maintenance tasks which require special tools, equipment, and/or knowledge
to accomplish and should be performed only by an authorized Generac Service Dealer.
4A mid-level inspection of the generator set to insure it is ready to operate and carry the load when required, and
to identify any potential problem areas.
Performed annually or following each 100 hours of operation of the unit and requires approximately 4.0
man-hours per unit to complete.
This inspection contains some maintenance tasks which require special tools, equipment, and/or knowledge
to accomplish and should be performed only by an authorized Generac Service Dealer.