GE 239 Instruction Manual page 44

4 PROGRAMMING
meter will indicate how much charge is left in the memory to give a rough idea of the lockout time
remaining. Alternately, this output can be programmed as thermal capacity  0$ (4 mA = 0%,
20 mA = 100% i.e. motor tripped) and connected to a programmable controller or DCS as a sig-
nal for process control. It might typically be used to reduce the feed on to a conveyor as the con-
veyor motor thermal capacity approached 100%.
c) RS485 SERIAL PORT
• SERIAL COMMS FAILURE ALARM: If loss of communications to the external master is required
to activate the alarm relay, select ON. In this case an absence of communication polling on the
RS485 communication port for 60 seconds will generate the alarm condition. Disable this alarm
output if communications is not used or is not considered critical.
• SLAVE ADDRESS: Enter a unique address from 1 to 255 for this particular relay on the RS485
communication link. This setpoint cannot be changed via the RS485 port. A message sent with
address 0 is a broadcast message to which all relays will listen but not respond. Although
addresses do not have to be sequential, no two relays can have the same address or there will
be conflicts resulting in errors. Generally, each relay added to the link will use the next higher
4
address, starting from address 1.
• BAUD RATE: Enter the baud rate for the terminal RS485 communication port, which may be
selected to one of  ,  ,  ,  , or   baud. All relays on the RS485 communication
link and the computer connecting them must run at the same baud rate. The fastest response will
be obtained at 19200 baud. Slower baud rates should be used if noise becomes a problem. The
data frame consists of 1 start bit, 8 data bits, 1 stop bit and a programmable parity bit, see 6 
6(783?56 6(5,$/ 3257?3$5,7< . The baud rate default setting is 9600 baud.
• PARITY: Enter the parity for the terminal RS485 communication port, which may be selected to
one of (9(1 , 2'' , or 121( . All relays on the RS485 communication link and the computer con-
necting them must have the same parity.
d) DEFAULTS
• LOAD FACTORY DEFAULTS: When the 239 is shipped from the factory all setpoints will be set
to factory default values. These settings are shown in the setpoint message reference figures. To
return a relay to these known setpoints select <(6 and press the
is displayed and then momentarily remove power to the 239. It is a good idea to first load factory
defaults when replacing a 239 to ensure all the settings are defaulted to reasonable values.
CLEAR PRE-TRIP DATA: When <(6 is selected in this setpoint and the
•
all of the pre-trip data in $ 67$786?/$67 75,3 '$7$ will be cleared and the following flash message
will be displayed for 3 seconds.
If the pre-data is cleared while a trip is still present, all pre-data except for "CAUSE OF LAST
TRIP" will be cleared.
CLEAR STATISTICS DATA: Select <(6 and press the
•
motor maximum starting current, and running time.
4-6
Courtesy of NationalSwitchgear.com
PRE-TRIP DATA
CLEARED
239 Motor Protection Relay
4 PROGRAMMING
key while this message
STORE
key is pressed,
STORE
key to clear all motor statistics,
STORE
GE Multilin