KEB COMBIVERT R6-S Series Instruction Manual page 11

2.
Different
Ground Po-
tentials
Fuse Sizing
with Isolation
Transformer
Prevent
disturbances
Automatic
Restart
Not Short-
Circuit Proof
(Supply)
When using components without isolated inputs / outputs, it is necessary that equal potential
bonding exist between the components to be connected (e.g. through the equalizer). Disregard
can cause destruction of the components by the equalizing currents.
When the R6 unit is supplied through an isolation transformer, the maximum allowable fuse
size is dictated by the size of the transformer as defined in the National Electric Code (NFPA-
70 or CSA 22.1). As per Article 450-3(B) of NFPA-70 (similar statements can be found in CSA
22.1), the max fuse size is defined in table 450.3(B) with a rating not greater than 125% of
the rated secondary current. In the case of multiple secondaries, it is the rated value of the
winding which the unit is supplied from. In this case it is to be assumed that the end customer
will fuse the transformer primary side with fuses exceeding 125% of transformer rated input
current. The value of this secondary fuse may be less than the max fuse value listed in the
technical data section 3.1 of this manual. The fusing of the transformer supercedes the fuse
rating of the unit because the value required for the transformer is lower than the max value
with which the unit was tested.
Trouble-free and safe operation of the COMBIVERT R6 is only guaranteed when the
connection instructions below are strictly followed. Incorrect operation or damage may result
from incorrect installation.
• Pay attention to the line supply voltage.
• Supply connection must be a symmetrical, center-grounded wye.
• Install power cables and control cables separately (>6.0 inches (15 cm) separation).
• Use shielded / twisted control lines. Connect the shield at one end to the COMBIVERT
R6-S GND terminal!
• Only use suitable circuit elements to control the logic and analog inputs, whose contacts
are rated for extra-low voltages.
• The heatsink of the COMBIVERT R6 must be well grounded. Shields of large power
cables must be directly and securely attached to both the inverter GND terminal and the
motor ground terminal. Remove paint finish where necessary.
• Ground the cabinet or the system with the shortest connection to the main ground point
(avoid ground loops)
• Use exclusively the commutation choke or harmonic filter specified by KEB.
• The average value of the supplied DC current may not exceed the maximum DC current.
• If several frequency inverters are connected to the COMBIVERT R6, the maximum
permissible DC bus capacities of all connected frequency inverters must be considered
during supply operation (see technical data).
• A ferrite ring must be installed over both + and - DC bus connections to the
COMBIVERT R6 unit to limit common mode noise on the DC bus.
The COMBIVERT R6 can be adjusted in such a way that the unit will restart automatically
after an error (e.g. single phase brown out or loss). System design must take this into account.
If appropriate, additional monitoring or protective features should be added where necessary.
The COMBIVERT R6 is not short-circuit proof as a power supply input ! If the I2t - protection is
adapted with a class gR fuse, a conditional protection at supply input is possible. If necessary
the short-circuit protection at DC output is ensured by internal class aR fuse.
Safety Instructions
US - 11