NORD Drivesystems B1092 - Manual (Page 45)

www.nord.com B1092-GB -45-
7. Data Sheets
Translated extract from Data Sheet 02
of the EU Prototype Test Certificate PTB 07 ATEX 3053 X
for the three-phase motor, type 1MA7 166-4…
Monitoring devices
To prevent impermissible heating due to overload, the motors are monitored by connection to a device for
direct temperature monitoring in combination with defined setting data of the inverter.
Due to the special characteristics of motors supplied by inverters and the adapted monitoring device,
details of the relationship I
A
/I
N
and the heating time t
E
are not required for motors operated by inverters.
The type of device for direct temperature monitoring has been tested by the Physikalish-Technische
Bundesanstalt and consists of three DIN 44082 type M 120 PTCs installed in the windings and a function-
tested triggering device according to Guideline 94/9/EU.
With a line current of 186.7 A and a blocked shaft, the PTC must trigger after 22 s (± 20 %) assuming a
cold condition (20 °C).
By means of the temperature monitoring device, temperature class T3 as per EN 60079-7 is complied with.
Inverter setting data
In combination with the aforementioned monitoring device, the following inverter data must be set and
maintained during operation:
Minimum pulse frequency: 3 kHz
Short-term current limit: 1.5*I
N
Maximum overload time: 60 s
Minimum frequency f
min
: 5 Hz
Maximum frequency f
max
: 100 Y / 100 Δ Hz
Permissible duration of operation
at f
min
:
60 s
The maximum overload time and the permissible duration of operation at f
min
refer to a time period of 10
min.
The relationship of the torque to the frequency results from the permissible continuous current limit.
Sheet 2/3