Power Tech Generators PTS-30 Operator's Manual page 145

supplies this in-rush of starting current, the generator voltage dips temporarily. If the motor is too large for
the generator, the generator’'s voltage dips greater than 30 percent. This may result in the motor starter
de-energizing or the motor stalling.
Outdoor Operations –– Generators subjected to outside operation must be protected from the
environments by fiberglass or metal housings with the proper forced air (fan) ventilation. Direct generator
contact of rain, snow, or dust must be avoided. Space heaters are also recommended for certain
environmental conditions.
Sand & Dust –– Generator windings are protected against harsh environments. However, severe
conditions may demand further protection. Special enclosures and filters may be necessary to protect
the generator from contaminants carried into the generator by required airflow.
High Humidity & tropical Climates –– Although the normal generator windings are humidity and moisture
resistant, in service areas that are particularly moist or humid, such as tropical environments and all
marine applications, additional protection is recommended. Special winding insulations are available, as
well as space heaters, to compensate for these harsh environments.
Altitude & High Ambient Temperature Operations –– For applications over 1000 meters (3300 feet)
elevation or where the temperature of the ventilating air to the generator exceeds 40°C (104°F), de-rating
of the generator is necessary.
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Non-Linear Loading –– When subjected to non-linear loads, ge
heat in the generator rotor and stator. Solid-state electronic devices, such as SCR devices, can introduce
high frequency harmonics, which adversely affect the normal waveform of the generator. To account for
these phenomena, generators must be oversized. Please consult the factory when faced with a
significant non-linear load.
1000
ALTITUDE - METERS
2
2000 3000
rator output is affected, causing additional
12.5% de-rate
10.0% de-rate
7.5% de-rate
5.0% de-rate
2.5% de-rate
0.0% de-rate