Alarm And Tripping Limits - ABB DCS 500B Description

Functional Software description
Alarm and trip-
ping limits
68
See the jumper settings of the input range and constant current
generator in Chapter 2 "Standard hardware description". See also
paragraph "Analog Inputs" in this chapter.
There are parameters for thermal measurement (PT100, PTC) a-
larm limit and tripping limit. If the measured temperature reaches
the value set in the alarm parameter, the program gives an alarm
indication, MOTOR 1 TEMP. ALARM / MOTOR 2 TEMP. ALARM. If
the temperature keeps on rising and reaches the tripping limit, the
program trips the drive and gives a fault indication MOTOR 1
OVERTEMP. / MOTOR 2 OVERTEMP. Overtemperature fault be-
longs to tripping level 2, which means that in case of overtempera-
ture the main and field contactors will open. Fans keep running until
temperature falls below the alarm limit.
In the PT100-measurement the alarm and tripping limit parameters
are set directly as Celsius-degrees. In the case of thermistor meas-
urement (PTC) the limits are set as resistance values, (0...4000
ohms). The alarm limits are set into parameters:
Motor 1: MOT1.TEMP ALARM L (1402)
Motor 2: MOT2 TEMP ALARM L (1602)
The temperature tripping limits can be set by the:
Motor 1: MOT1.TEMP FAULT L (1403)
Motor 2: MOT2 TEMP FAULT L (1603)
If the above parameters are set to zero, the alarm and tripping limits
will not be supervised.
Example:
Analog input channel 2 (AI2) has been selected for PT100-
measurement of the motor windings (3 elements), and the analog
input channel 3 (AI3) has been selected for PT100-measurement of
the motor bearings (2 elements). It is supposed that the alarm and
tripping limits of the motor winding are 110°C and 120°C. The alarm
and tripping limits of the bearings are 40°C and 50°C. The settings
in this case are:
AI2 CONV MODE (107) = 5
AI3 CONV MODE (110) = 4
MOT1.[TEMP IN] (1401) = 10107
MOT1.TEMP ALARM L (1402) = 110
MOT1.TEMP FAULT L (1403) = 120
MOT2.[TEMP IN] (1601) = 10110
MOT2.TEMP ALARM L (1602) = 40
MOT2.TEMP FAULT L (1603) = 50
(connect to output AI2: 10107)
(connect to output AI3: 10110)
DCS 500 Software Description