KEB Combivert R6 Instruction Manual - page 8
US - 8
Safety Instructions
Different
Ground
Potentials
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.
Fuse Sizing
with Isolation
Transformer
When the R6 unit is supplied through an isolation transformer, the maximum allowable fuse
size is dictated by the size of the transformer as defi ned 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 defi ned 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.
Prevent
Disturbances
Trouble-free and safe operation of the 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 R6-N 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 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 fi nish where necessary.
•
Ground the cabinet or the system with the shortest connection to the main ground point
(avoid ground loops)
•
Use exclusively the regen choke or harmonic fi lter specifi ed 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 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 R6 unit
to limit common mode noise on the DC bus.
Automatic
Restart
The 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.
Not Short-
Circuit Proof
(Supply)
The 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.