Global Power Technologies
SERVICE AND MAINTENANCE
05585 rev11 | Model 8550-SD
Page 22 of 53
If the TEG was not left operating at Set Power during the last visit, investigate the reason for
this. Check the System Performance Log for additional notes or remarks from the previous
service check.
If the TEG was left operating at Set Power during the last visit and is now not producing Set
Power, consider the following causes:
•
Change in fuel pressure:
Refer to the last entry in the log and determine if the fuel pressure has changed. If so,
re-adjust the fuel pressure to the last entry.
If this returns the Power Unit output power to within 10 Watts of Set Power, you can
proceed with the basic service outlined in Section 5.2.
•
Obstructed air flow:
Check for obstructions at the Heat Pipe fins, Air Inlet Screens, and Air Shutter. Perform
the Air Shutter test, see
Section 5.1.4.
If this returns the output power to within 10 Watts of Set Power proceed to Section 6.2
– Basic Service.
•
Change in fuel quality:
In order to maintain a constant output power, it is essential that the TEG be supplied
with a fuel of constant heating value.
•
Poor cooling by heat pipes:
Check to make sure that the
Heat Pipe fins are not obstructed by debris or dust. Check
that the Heat Pipe ends are warm. Test the cooling system as outlined in
Sections 6.3.
•
Change in customer load:
An overloaded TEG can see a minor to severe decline in output power and voltage.
Verify that the connected load isn't attempting to draw more power than the TEG's Set
Power.
If the above causes have been ruled out, the TEG may require more than just the basic service
Keep the TEG operating for now and refer to
Section 6.1.1
to isolate the cause of low Set Power
condition.
5.1.1
LOW SET POWER DIAGNOSTIC
The procedures in this section are designed to isolate the cause for the Power Unit to have low Set
Power. Perform these tests only if previous tests during the Power Check indicate that they are
required.
For the following test to be accurate, the TEG must have been operating continuously at the
customer voltage setpoint for the last 12 hours.
There are three basic reasons for the Set Power to be low. These are:
•
low or inefficient heating by the burner and fuel system,
•
poor or inefficient cooling, or
•
a faulty or damaged Power Unit.