
5
Electrical installation
Cable entries
Operating Instructions – EDR..71 – 315, EDRN63 – 315
58
5.4
Cable entries
The terminal boxes have metric threaded holes according to EN 50262 or NPT
threaded holes according to ANSI B1.20.1-1983. All bores are equipped with explo-
sion-proof closing plugs upon delivery.
For a correct cable entry, replace the closing plugs by cable glands with strain relief
that are certified for use in the respective hazardous location. Select the cable gland
according to the outer diameter of the cable used. For the tightening torque of the
cable entry, refer to the operating/installation instructions or the EU type examination
certificate of the cable glands. The IP degree of protection of the cable entry must be
at least as high as the IP degree of protection of the motor.
Only use connection glands with screw heads that fit into the existing countersink.
The following table shows the sizes of the flat bottom counter sinking with the corres-
ponding screw sizes:
Counter sinking in
mm
19
24
30
35
45
56
64
75
Screw fitting
M12
M16
M20
M25
M32
M40
M50
M63
All cable entries that are not required must be sealed off with a closing plug after com-
pletion of the installation in order to maintain the degree of protection. A closing plug
may only be replaced with another explosion-proof closing plug.
5.5
Equipotential bonding
In accordance with EN 60079-14, the unit must be connected to an equipotential
bonding system. A second grounding screw is available for this connection on the out-
side of the terminal box. Observe chapter
Improving the grounding (EMC), HF
5.6
Wiring notes
During installation observe the safety notes in chapter 2 and 5.
5.6.1
Protecting the brake control system against interference
Brake cables must always be routed separately from other unshielded power cables
with phased currents to prevent interference with brake control. In particular, power
cables with phased currents include:
•
Output cables from frequency inverters and servo inverters, soft start units and
brake units
•
Supply cables for braking resistors and similar options
For line-operated motors and when using AC and DC circuit cut-off, the connection
between the brake rectifier and the external switch contact must be in a different
power cable that is separate from the motor power supply.
25896334/EN – 06/2019