
B9300 Power Reference Unit
POWER REF. UNIT
B9300
ON
100
MAINS-SWITCH
POWER 
REFERENCE 
B9300-XX-14
LOAD SHARER
T4400
LOAD SHARER
T4400
BUS
GRID
MAINS-SWITCH
AUT./MAN.
POWER 
REFERENCE 
B9300-XX-10
MOTOR 
SUPPLY
DECR.INCR.
GEN.
1
LOAD SHARER
T4800
AUT./MAN.
LOAD SHARER
T4800
MOTOR 
SUPPLY
DECR.INCR.
GEN.
1
BUS
GRID
• Setting of generator capacity via 
SELCO load sharers
• Adjustable from 0 to 100%
• DC output (0 - 1V DC, ±1V DC, 
0 - 3V DC or 0 - 5V DC)
• Knob for manual control
• Screw lock for knob
• 50 hours burn-in before test 
• Ambient temperature range: 
-20°C to +70°C
• Flush mounted unit
Application
The B9300 Power Reference Unit is 
 applied for setting the capacity to be 
provided by the engine driven generator(s) when the generators are 
 operated in parallel with a grid (utility) 
or a shaft generator.
The B9300 is used as a complementary 
unit to SELCO’s range of load sharers 
(Load Sharer type T4300, T4400 and 
T4800). 
Function
The load sharer will adjust the power of 
an engine driven generator according to 
the setting of the knob placed on the 
front panel of the Power Reference  
Unit. The setting is 0 - 10 (equivalent to 
0 - 100 %). 
A finger screw is provided for locking 
the dial.
to half of its original setting. If instability 
occurs, the dead band zone should be 
increased by increasing the STABILITY 
setting on the T4800.
 tiometer Type and B9300 Power 
 Reference Unit is available. The unit is 
specified E7800-9x. For details, please 
refer to the data sheet for the E7800 
 Motorized Potentiometer. This data 
The B9300 Power Reference Unit is for 
flush mounting and it has standard 
sheet can be downloaded from our web 
site www.selco.com 
 instrument dimensions 96 x 96 x 80mm 
(H x W x D).
Example of setting: 
Generator rating: 695A at PF 0.8
Active current: 695 x 0.8 = 556A
Option
In order to obtain remote setting of the 
power reference function, a combina tion of Selco’s E7800 Motorized Poten- 
Current transformer: 800/5
Maximum on dial: 10
Full load on dial: 10 x 556/800 = 6.95 
(69.5%)
The same Power Reference Unit can  
also be connected to several load  
sharers where a multi engine installa tion is operating in parallel with a grid 
supply.
The output of the B9300 Power 
 Reference Unit (terminals 5 and 3) is 
connected to the parallel lines of the 
load sharer(s) (terminals 12 and 13).
The connection of terminal 5 of the 
B9300 Power Reference Unit and 
 terminal 13 on the SELCO T4800 Load 
Sharer will disable the frequency  
control function in the load sharer. This 
is used when running parallel to the 
grid (utility) or other frequency 
 determining power sources.
Please note that the dead band zone in 
the T4800 Load Sharer will be reduced 
Fig. 1. Application Diagram. B9300 with T4400. Fig. 2. Application Diagram. B9300 with T4800.

Fig. 3. Dimensions.
75mm
26
96mm
Cut out 92 x 92mm
96mm
SELCO Worldwide
Specifications
B9300 Power Reference Unit
Max. voltage  480V 
Voltage range  90 - 120% 
Consumption 
DC output  0 - 1V DC, ±1V DC, 0 - 3V DC or 0 - 5V DC 
Operating temperature  -20 to +70°C 
EMC  CE according to EN50081-1, EN50082-1, EN50081-2, 
  EN50082-2
Burn-in  50 hours before final test 
Weight  0.7kg 
Dimensions  96 x 96 x 80mm (H x W x D) 
Panel cut out  92 X 92mm (H x W)
The specifications are subject to change without notice.
Type Selection Table
  Terminals 
Type  1-2  Function 
B9300.0010  220-240V  Output 0 - 1V DC 
B9300.0030  220-240V  Output 0 - 3V DC, to be used with T4300/T4400-xx 
B9300.0040  220-240V  Output 0 - 3V, to be used with T4300/T4400-xx,
    max. adjustment from 1.5 - 3V DC 
B9300.0050  100-110V  Output 0 - 1V DC 
B9300.0060  380-450V  Output 0 - 1V DC 
B9300.0070  380-450V  Output ±1V DC 
B9300.0090  415-480V  Output 0 - 1V DC
Other voltages and combinations are available on request.
2VA at UN  
Main office: 
SELCO A/S
Betonvej 10 
DK-4000 Roskilde 
Denmark 
Phone: + 45 7026 1122 
Fax:  + 45 7026 2522 
e-mail: selco.dk@selco.com 
www.selco.com
B9395-72 E