Type of compressor = Centrifugal air compressor
Capcity = 6000 Nm3/hr
Stages = Three stages
Prime mover= Motor of 1 MW
FLC of Motor = 186 Amperes
Problem:

Compressor motor high high current (mpere increased from 148 to 206 A ) & Low pressure side (1st stage) vibration increased from 2.8 to 5.6 um alarms actuated having no effects on high pressure side ( 2nd stage). Also observed that Return lube oil temperature increased from 75 to 120 C and lube oil reservoir temperature increased from 68 to 120C. Inlet lube oil temperature increased from 48 to 57C. On investigation lube oil circuit all accessories found normal i.e. pcvs , thermostatic valve, lube oil cooler & PSV. Moreover, 1st stage bearing housing conditions found absolutely normal.

What could be the reason for increase in lube oil temprature.

If all mechanical functions are normal the causes are limited. How many hours on what type of fluid? Have you performed an oil analysis?

Too low viscosity perhaps?

Jmorgan states a good point, get the device info, lube recomendations and an oil analysis.

MHAPAK,

1. Why the compressor not giving you alarm when oil reservoir temperature was > 60 C ?
2. why it was not giving alarm when oil supply temperature was exceeding 50 C?

Have you check your oil cooler is working properly or not?

regards,

Nurudin