
Planning the electrical installation 43
Protecting the contacts of relay outputs
Inductive loads (relays, contactors and motors) cause voltage transients when switched
off.
When you connect inductive loads to the customer I/O, equip the loads with noise
attenuating circuits (varistors, RC filters [AC] or diodes [DC]) to minimize the EMC
emissions at switch-off. If they are not suppressed, the disturbances can connect
capacitively or inductively to the other conductors in the control cable and cause a
malfunction.
Install the protective component as close to the inductive load as possible. Do not install
protective components at the relay outputs.
1) Relay outputs, 2) varistor, 3) RC filter, 4) diode
230 V AC
230 V AC
+24 V DC
-
1
2
3
4
Summary of Contents for PVS800-57B
Page 1: ... ABB SOLAR INVERTERS PVS800 57B central inverters Hardware manual ...
Page 4: ......
Page 8: ...8 ...
Page 16: ...16 Safety instructions ...
Page 30: ...30 Operation principle and hardware description ...
Page 32: ...32 Planning the mechanical installation ...
Page 62: ...62 Dimension drawings Cabinet dimensions ...
Page 63: ...Dimension drawings 63 ...
Page 64: ...64 Dimension drawings Cabinet attachment points ...
Page 65: ...Dimension drawings 65 ...
Page 66: ...66 Dimension drawings AC and DC cabling lead throughs ...
Page 67: ...Dimension drawings 67 ...
Page 68: ...68 Dimension drawings AC cabling ...
Page 69: ...Dimension drawings 69 ...
Page 70: ...70 Dimension drawings DC cabling ...
Page 71: ...Dimension drawings 71 ...
Page 72: ...72 Dimension drawings ...