en – Original Instructions
24
SCUBA DRY – Additional Installation, Operation and Maintenance Instructions
4.4.3
Guidelines for the electrical control panel
NOTICE:
The electric panel must match the ratings on the data plate. Improper combinations could
damage the motor.
•
Install appropriate devices for protecting the motor from overloads and short circuits:
Motor
Safety features
Single-phase
•
Automatic reset thermal-ampere protection, in-built (motor protector)
•
From short circuit, by the installer: aM fuses (motor start-up), or thermal magnetic switch with C
curve and Icn ≥ 4.5 kA, or other similar device.
Three-phase
•
Thermal, by the installer: trip class 10 A overload thermal relay + aM fuses (motor start-up), or start
class 10 A motor protection thermal magnetic switch
•
From short circuit, by the installer: aM fuses (motor start-up), or thermal magnetic switch with C
curve and Icn ≥ 4.5 kA, or other similar device.
•
If required, install phase failure sensitive thermal relays.
4.4.4
Operation with frequency converter
Single-phase and three-phase motors can be connected to a frequency converter for speed
control.
•
The converter exposes the insulation of the motor to a greater load, determined by the
length of the connecting cable: observe the requirements of the Manufacturer of the
frequency converter
•
The minimum frequency must not fall below 25 Hz
•
The head of the unit must never be below 2 m (6.5 ft)
•
For applications requiring silent operation, install an outlet filter between the motor and the
converter; a sinusoidal filter can reduce the noise even further
•
The conditions of installation must guarantee protection against voltage peaks between the
terminals and/or dV/dt in the table:
Motor size
Voltage peak, V
dV/dt, V/µs
up to 90R (500 V)
< 650
< 2200
from 90R to 180R
< 1400
< 4600
over 180R
< 1600
< 5200
