The electrical equipment of Group II are classified according to the character
of explosive atmosphere, for which they are intended for.
For the degree of protection "pressure resistant casing "d"" and "intrinsic safety
category "i"", all electrical equipment of Group II are classified into IIA, IIB and
IIC (see appendix A according to EN 50014:1992).
For all degrees of protection, the equipment of Group II has to be labeled subject
to its maximum surface temperature.
Temperature classes
The maximum surface temperature for electrical equipments of Group I has to
be indicated in the testing documents.
Electrical equipment of Group II are classified and labeled and have to be either:
●
classified preferably in a temperature class in compliance with
;
●
or labeled with the particular maximum surface temperature;
●
or, if applicable, labeled with the specific gas for which the apparatus is
intended for.
Temperature class
Maximum surface temperature
°C
T1
450
T2
300
T3
200
T4
135
T5
100
T6
85
Fig.9-3:
Classification of the maximum surface temperature in classes for elec‐
trical equipment of Group II
9.1.2
Application Conditions for MKE Motors
General
Connection conditions
The motors are only allowed to operate with the Rexroth drive control devices
Indradrive, DIAX04, EcoDrive, and DURADRIVE. Controllers of other manu‐
facturers are not permitted.
The clamp terminals in the terminal box must be screwed on tightly.
Do not disconnect or connect connectors in explosive areas!
Grounding
Speed-controlled drive systems contain unavoidable discharge currents above
ground. For this reason, the motors have to be grounded over the motor cable
and over a separate ground wire with min. 4 mm
2
of cross-section, as specified
in the terminal diagram. Check that the position of the grounded conductor is
fixed before commissioning.
If the protective conductor in the motor cable and the second separate protec‐
tive conductor on the motor housing are not connected or are interrupted by
corrosion or other defects during their lifetime, the discharge current flows (as
leakage current) over conducting housing parts. This has to be prevented with
the above-mentioned measures. (ATEX-Directive 94/9/EG, appendix II, Cap.
1.2.3 and Cap. .1.3.3, 1.4)
Risks of corrosion
Corrosion of the motor housing due to aggressive substances (such as certain
coolants, lubricants, cutting oils or salt mists) is to be prevented.
Emergency stop
Stored energy in the drive devices circuit has to be degraded or isolated as
soon as possible via pressing the emergency stop, so that in the case of failure
Project Planning Manual | Rexroth MKE Synchronous Motors
Electric Drives
and Controls
| Bosch Rexroth AG
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Operating Conditions and Application Notes
