NORD Drivesystems B1091 - Manual (Page 9)

www.nord.com B1091-GB-4613 -9-
5. Motors with ignition protection
class "increased safety Exe"
Each machine must be protected against impermissible development of heat by means of a current-
dependent delayed protection switch tested for operation by an approved facility, with phase-failure
protection compliant with VDE 0660 or an equivalent system in all phases. The protective system must be
set to the rated current. If windings are connected in a delta circuit the trips must be connected in series with
the winding phases and set to 0.58 times the rated current. If such a configuration is not possible, additional
precautions are necessary (e.g. thermal machine protection).
If the rotor jams, the protective system must shut down within the t
E
-time specified for the respective
temperature class.
Electric machines for heavy-duty starting (ramp time > 1.7 x t
E
-time) must be protected by a start-up
monitoring system in accordance with the provisions of the EC prototype test certificate.
Thermal machine protection by means of direct thermal monitoring of the winding with PTC thermistor
temperature sensor is permissible if this is documented and stated on the name plate.
Do not connect any voltage higher than 30V to the PTC thermistor temperature sensor!
If the only protection is a PTC thermistor temperature sensor, a performance-tested, PTC tripping device
certified by a designated body must be used. The PTC tripping device must be provided with the following
marks with regard to the degree of protection:
II (2) G
The following standards and regulations must be observed for the installation of electrical systems
in explosion hazard areas: DIN EN 60079-14 (VDE 0165-1), the Technical Regulations for Operational
Safety (TRBS), the industrial safety regulations and the explosion protection regulations (Ex-RL).
Other regulations must also be observed, if applicable. For all countries the appropriate national
regulations must be observed.
Operation in conjunction with an inverter must be explicitly certified. The separate manufacturer's information
must be observed. For Exe protection the motor, inverter and protective systems must be identified as
belonging together and the permissible operating data must be defined on the joint EC prototype test
certificate. The levels of voltage peaks generated by the inverter may be unfavourably influenced by the
connecting cable installed between the inverter and the electric machine. In the system comprising the
inverter, the cable and the electric motor, the maximum value for voltage peaks at the connecting terminals
on the machine must not exceed the figure specified in the separate manufacturer's instructions. In addition,
the EMC Directive must also be observed.
Repairs must be performed by NORD or accepted by an officially recognised expert. The work must be
identified by means of an additional repair plate. With the exception of standardised, commercial and
equivalent parts, only genuine spare parts must be used (see spare parts list): this particularly applies to
seals and connecting parts.
In the case of motors with closed condensation holes the threads of the plugs must be recoated with Loctite
242 or Loxeal 82-21 after condensation has been drained off. After this, the plugs must be reinserted
immediately. The electrical connections must be checked at regular intervals.
The connection terminals, protective earth terminal and equipotential bonding terminal must be inspected to
make sure they are firm. When doing so, check to make sure that the cable entry, cable gland and terminal
box seals are in good condition.
All work on electric machines must be performed with the machine vertical and with all terminals
disconnected from the mains.
The motor must be removed for measurement of the installation resistance. The measurement must not be
performed in the explosion hazard area. As soon as measurement has been completed, discharge the
connecting terminals again by shorting them in order to prevent any spark discharges occurring in the
explosive area.