Instruction manual V 2.3
13
PWM 230 - PWM 400 - PWM 400/7.5
Instruction manual
2.3.1
Connection of the PWM 400 – PWM400/7.5 to the power supply line
Normally PWM devices are equipped with a power cord labelled “Line” to connect to a 380V-415V 50-60Hz
three-phase electric line. For versions that are not, the line must be connected to the 4-ways terminal “J2-J8”
with “LINE” silk-screened on it (see Figure 6).
Figure 6: Power supply line input terminals
If the installed electro pump’s power equals the maximum allowed one, the power cord wires’ section should
be greater than a given value, depending on the cord’s length. Table 5 shows the minimum wires’ section as
a function of the cord’s length.
Length of the line (meters)
Min. section of every conductor (mm
2
)
0 - 50
1.5
50 - 85
2.5
85 - 140
4
Table 5: Minimum section as a function of power cord’s length for PWM 400
If the installed pump’s power is lower than the maximum allowed one, the power cord’s wire section can be
reduced proportionally to the power decrease (for example if the total power halves, the section will be
halved).
PWM 400 and PWM400/7.5 already provide internal current protections. If a thermal magnetic circuit breaker
is installed, its rated current must be 16 A.
Connection of the power line to PWM must include a ground wire whose impedance, must comply with the
safety regulation in force in the country of use. The total grounding resistance must not exceed 100 Ohm.
2.3.2
Electrical connection of the electro pump to PWM 400 – PWM400/7.5 devices
The supply voltage of the motor of the installed electro pump must be 400V three-phase.
Phase current absorbed by the utility connected to PWM400 must not exceed 13A rms and 7.5A rms for
PWM 400/7.5.
Three-phase motors whose rated voltage differs from 400V cannot be operated with PWM 400 and PWM
400/7.5.
Check the motor connection ratings to fulfil the above condition.
Typically, when line voltage is 400V, if the pump’s power is lower than 5.5 kW, a star wiring is used.
Conversely, if the pump’s power exceeds 5.5 kW, a delta wiring is used.
Figure 7 shows how to make the proper connections.