Analog Output - GE 239 Instruction Manual

CHAPTER 4: PROGRAMMING
4.2.2

Analog Output

239 MOTOR PROTECTION RELAY – INSTRUCTION MANUAL
Courtesy of NationalSwitchgear.com
• DEFAULT MESSAGE BRIGHTNESS: The brightness of the displayed messages can be
varied with this setpoint. The brightness set by this setpoint will be used when the
default messages are being displayed. The brightness defaults back to 100% when:
•trip is present
•alarm is present
•any one of the keys on the 239 keypad is pressed
•the 239 is turned off and on
When
S1: 239 SETUP\PREFERENCES\DEFAULT MESSAGE TIME
brightness will adjust to set level after 5 minutes have elapsed since the 239 keys were
last pressed. The 239 status must also be NORMAL to display the set brightness. If no
default message is programmed, the display brightness will adjust to the set level
after the programmed time in message
has elapsed.
MESSAGE TIME
NOTE: Message brightness control is available only with the VFD display option.
• BLOCK KEYPAD TRIP RESETS: This feature blocks any attempts made to reset the
present trip using the RESET key on the 239 keypad. When this feature is enabled and
a trip is present, pressing the RESET key will display the following flash message for 3
seconds.
RESET NOT POSSIBLE
KEYPAD RESET BLOCKED
This feature is applicable to trips only. The function of the
areas (i.e. reset alarms, remove default messages, etc.) is not affected.
• OVERLOAD PICKUP DISPLAY ENABLE: When an overload pickup has occurred, this
setpoint determines whether the 239 front display is automatically updated with the
time to overload trip. When this setpoint is programmed to
have no effect on the display. The pickup LED indicator and overload protection are
not affected by this setpoint.
• ANALOG OUTPUT TYPE: If the relay is to be used in conjunction with programmable
controllers, automated equipment, or a chart recorder the analog output can be used
for continuous monitoring. Choose from one of the following parameters for output:
THERMAL CAPACITY , AVERAGE PHASE AMPS
percentage of full load), or
be selected for continuous analog output, all values are available digitally through the
communications interface. See Section 2.1.3 ANALOG OUTPUT (OPTION) (18/19/20) on
page 2–26 for a description of current output scaling. Applications include using a
computer to automatically shed loads as the motor current increases by monitoring
current as a percentage of full load current or a chart recorder to plot the loading of a
motor in a particular process.
• ANALOG OUTPUT RANGE: In processes where the motor loads are varied and
operated at near the motor full load such as in grinding or in conveyor systems it is
useful to know how close the relay is to tripping so the load may be adjusted
S1: 239 SETUP\PREFERENCES\DEFAULT
, MOTOR LOAD
. Although a single parameter can
RTD1/2/3 TEMPERATURE
is set to , the
OFF
key in other
RESET
, an overload pickup will
NO
(phase current as a
4–15