Armstrong World Industries ACUM140 Manual De Usuario

 

AR-EXP-CUMMINS-07-00 

 

OWNERS MANUAL  

In case of complete overhaul of genset, the bearing of the 
generator should be changed. 
On request prelubricated bearings with regreasing system 
can be mounted. When regreasing use 20/ 30 grams of 
grease. 
Following types of grease are to be recommended for nor-
mal application: 
 
MOBIL OIL: MOBILUX 3 
SHELL: ALVANIA 3 
AGIP: GR MW 3 
ESSO: BEACON 3 
 
9.3.  VOLTAG REGULATOR 

 
The generators are provided with automatic voltage regula-
tor. The AVR is provided with potentiometers to adapt the 
characteristics of the AVR to different operating conditions. 
 
The AVR is provided with adjustable stability circuitry to 
allow operations in a wide range of applications.  
 
The AVR is equipped also with protecting  circuit allowing 
the generator to operate underspeed if not loaded. 
 
 ATTENTIONI: it is not advisable to have the generator oper-
ating loaded when the frequency (speed) is below the rated 
value: this kind of operation is an overload for the whole 
generator excitation system. 
 
CONNECTION OF AVR 
The AVR is connected to the terminals of the generator and 
to exciter FAST-ON terminals. 
 
USE OF POTENTIOMETERS 

P1/VOLT- Potentiometer for adjusting the output voltage of 
the generator; it allows a wide range of voltage setting (i.e. 
between 350 and 470 V; or between 170 and 260 V de-
pending on winding connections)). When resetting the po-
tentiometer, the voltage has to be set in the range +5%,-5% 
around the rated voltage of the machine. In order to obtain 

a finer regulation, or to adjust the voltage from control 
panel or to limit the voltage range, it is possible to insert an 
external potentiometer. 
 
P2/FREQ- Potentiometer for changing the low speed protec-
tion. Usually it is set in order to reduce the excitation when 
the speed is 10 % below the rated value at 50 Hz. By re-
moving the bridge which is normally shorting the auxiliary 
terminals 60-Hz of the regulator, the low speed protection 
acts properly for 60 Hz. 
 
P3/STAB- Potentiometer for stability adjust. By rotating it 
clockwise the stability of the regulator increases, but the 
response time becomes longer. 
 
P4/AMP- Potentiometer for chancing the overexcitation limit 
device. The overexcitation limit device helps to protect the 
excitation system. This device is delayed to avoid transitory 
conditions (in case of overexcitation). 
 
On the AVR there is a protecting fuse. ln case it should be 
necessary to replace it, high speed fuses should be used; in 
addition  they  should  have  high  breaking  resistance  with  a 
rated voltage of 50OV, and rated current of 1OA. The AVR is 
connected to the terminals of the generator and to exciter 
using FAST—ON terminals.