
39
117
Motor Thermal Protection
(MOT. THERM PROTEC)
Value:
No protection (NO PROTECTION)
[0]
Thermistor warning (THERMISTOR WARNING)
[1]
Thermistor trip (THERMISTOR FAULT)
[2]
ETR Warning 1 (ETR WARNING 1)
[3]
✭
ETR Trip 1 (ETR TRIP 1)
[4]
ETR Warning 2 (ETR WARNING 2)
[5]
ETR Trip 2 (ETR TRIP 2)
[6]
ETR Warning 3 (ETR WARNING 3)
[7]
ETR Trip 3 (ETR TRIP 3)
[8]
ETR Warning 4 (ETR WARNING 4)
[9]
ETR Trip 4 (ETR TRIP 4)
[10]
Function:
The drive is able to monitor the motor temperature in two different
ways:
By a thermistor installed in the motor. The thermistor is connected
to one of the analog input terminals (53 or 54).
Calculation of the thermal load by the Electronic Thermal Relay
(ETR) is based on current, frequency and time. This is compared
with the rated motor current and the rated motor frequency. The
calculations take into account the reduced cooling of the motor at
low speeds.
ETR Tip 1 through 4 and ETR Warning 1 through 4 correspond to the
four drive setups. This enables the use of the ETR function to protect
up to four different motors if a different setup is used for each different
motor.
CAUTION
!
If multiple setups are used, be sure to program
complete motor data (parameters 102 through
106) and parameter 117 in each setup. This can
be done manually, or parameter 003 can be used
to copy all data from one setup into one or more
setup groups.
Motor Thermal Protection
The motor temperature is calculated on the basis of motor current,
output frequency and time. The graph shows the amount of time that the
drive can provide a current level to the motor at the rated motor
frequency, 20% of rated motor frequency and 200% of rated motor
frequency.
Description of choice:
Select No protection if no warning or trip is desired when the motor is
overheated.
Select Thermistor warning if a warning is desired when the motor
thermistor reaches its trip point.
Select Thermistor trip if a fault is desired when the motor thermistor
reaches its trip point.
Select ETR Warning 1 through 4, if a warning is desired when the
motor is overheated according to the ETR calculations.
The drive can also be programmed to give off a warning signal through
one of the digital outputs.
Select ETR Trip 1 through 4 if a fault is desired when the motor is
overheated according to the ETR calculations.