Can I switch to wireless control without removing my existing pushbutton wiring?
Yes. On ST100 and SF100 sets the manual pushbutton and the RF remote control can be used at the same time; the receiver relay contacts are wired in parallel with the existing button contacts. That way the plant keeps running from the buttons when the remote is charging or faulty, and you do not have to rebuild the panel from scratch for the changeover.
The method is simple: the receiver's relay contact is wired in parallel with the existing button contact. The same contactor coil is energised whether the button closes or the relay closes.
Points to watch in practice:
- Interlocking must not be compromised: the mechanical and electrical interlock that prevents the forward and reverse directions from being energised at the same time must remain valid for both the button side and the relay side.
- Limit switches must stay in circuit: the limit switches must be in series within the contactor coil circuit, not within the remote control. That way the limit is protected independently of the radio link.
- Emergency stop: the machine's hard-wired emergency stop circuit is not removed; the wireless remote control does not take its place.
- Labelling: mark in the panel which terminal comes from the RF receiver; it shortens fault finding later.
This parallel operation approach allows a gradual changeover, especially in plants that cannot stop production: the receiver is connected and tested first, and once the site operator has got used to it, wireless use becomes the primary method with the buttons remaining as a backup.
The full topic: Wireless remote control installation: pairing, relays, safety