Fig 4.4 TN-S networ
k
TT network
The mains in the figure is not very common and has problems with EMC requirements, which can only be fully met with in-
situ measures. The main characteristics are shown below:
a)
Direct mains connection (earthing point)
b)
NA
b)
All parts exposed to contact and shielding must be connected to earth
Fig 4.5 TT network diagram
4.3.4.2. Protection components
Fuses
Sizing network fuses: The size of fuses must be immediately greater than the sum of the currents of each module connected to
the power supply (with a limit of 54 A, as per the power supply size L50 and 128 for a size L150).
Example: In a system comprising three modules (one size 50 mm 4+6 A module, one size 75 mm 24 A module) a fuse with a size
immediately greater than 4+6+24 A=34 or a 36 A fuse will be used, in the instance that both axes are being used at once.
Safety switches for fault currents
According to EN60204-1 on the electrical equipment of machinery, a safety switch can be used for fault currents, provided it
complies with applicable regulations.
To protect from direct accidental contact, a safety switch for fault currents (dispersion) with a sensitivity of 30 mA must be
installed on each axis-module/power supply system
The DR2020 does not require fuses on the auxiliary power supply and on the DC BUS
337
TN-S network
The type of network shown in th
��
gure is the most widespread in Europe and has the following characteristics:
a)
Direct mains connection (earthing point)
b)
NA
c)
All parts exposed to contact and shielding must be connected to earth
L1
L2
L3
N
PE
c
a
TRAFO
POWER
CONNECTOR
L1
L2
L3
N
POWER
CONNECTOR
a
c
TRAFO
MAR2-E-191
37
e fi
