When the relays are at rest (normally closed position) the woofer coils are wired in series. Partial voltage when relays are connected in series When used with a DC load, connecting relays in series divides the voltage in two and it may be possible to interrupt a larger voltage than with a single relay. Thus countermeasures to suppress counter electromotive voltage are necessary. Can I parallel the contacts to get an effective 60A relay? Further, could I parallel two (or more) relays and get even more current capacity? I see two possible problems. Can I connect the 2 relays in series by supplying 24V DC so that there will be 12V DC drop across each of the 2 relays? What will be the behaviour of the relay coils, and the reverse coil voltages when connected in series? what do you think the behavior will be? It will work fine if the relays have. This handbook covers the code of practice in protection circuitry including standard lead and device numbers, mode of connections at terminal strips, colour codes in multicore cables, dos and donts in execution. Also principles of various protective relays and schemes including special protection. When designing and installing power distribution systems, engineers and contractors select surge protective devices (SPDs) to protect electrical equipment and systems from transient overvoltages. To do so, specifiers must understand the differences between parallel-connected and series-connected.
