The remote control does not work, what should I check and in what order?
Start at the power and work towards the power circuit. Whether the relay pulls in splits the fault into control side and power side and shortens the hunt.
Follow the order from the power supply forwards: the charge or battery state of the remote control, the supply and the fuse of the receiver, the antenna connection, whether the pairing has been kept, whether the relay output pulls in, the contactor coil circuit and the limit switches. The single question that splits the fault in two is this: is the relay pulling in? The most frequent mistake is skipping the order and changing parts at random.
Checklist in order
- Remote control power: on the ST100/ST200 the Li-Po charge state, on the SF100/SF200 that the 3×AAA cells are fresh and fitted the right way round.
- Receiver supply: measure the voltage at the receiver terminal. The SF100 and ST100 receivers are powered from 12/24V DC or 220V AC; verify the supply rating of your own set from the product page and from the manual. Check the supply fuse.
- Antenna: the tightness of the connector, a broken or crushed cable, the antenna being outside the panel and in a vertical position.
- The critical split — is the relay pulling in? When the button is pressed, listen for the click of the relay in the receiver or measure its contact.
- If it does not pull in, the problem is on the remote control to receiver link: the pairing may have been lost, so repeat the teaching procedure in the manual; assess the range and the interference conditions.
- If it pulls in but the machine does not move, the problem is in the power circuit: the contactor coil, the NC contacts of the limit switches, the thermal relay, phase failure, the motor connection.
- Try it with a spare remote control. A second remote control taught to the same receiver localises the fault within seconds.
Why this order
The order goes from the cheapest and most likely cause towards the most expensive and rarest. The great majority of faults reported on site end at the trio of battery, supply and antenna; taking the receiver off without eliminating these three is a waste of time. The second reason is access: the battery and the terminal can be measured without stopping the machine, whereas opening the contactor panel requires isolating the power.
From symptom to likely place
| Symptom | Place to look first | Its verification |
|---|---|---|
| No response at all | Remote control battery, receiver supply | Measure the voltage at the terminal |
| Works close by, cuts out at a distance | The antenna and its placement | Bring the antenna outside the panel |
| Some movements do not work | Limit switches and interlocking | Measure the contact state |
| The relay pulls in, no motor | Contactor and power circuit | Measure the coil voltage |
| Runs out quickly in the cold | Battery and charge state | Repeat it with a new battery |
Frequent mistakes
The first is deleting the pairing while hunting for the fault: if the problem is not in the pairing it is not solved, and the other remote controls on site can drop out as well. The second is putting the antenna inside the panel and closing the door, then looking elsewhere for the reason when the range falls. The third is testing at a single distance and saying “it works”. The fourth is changing more than one thing at a time: if you renew the battery, the antenna and the pairing together, you will not learn the cause even if the fault goes away. The fifth is not recording the result of a measurement.
What this list does not solve
The list is for the control chain. If the motor is mechanically jammed, if the brake is not releasing, if the phase sequence is wrong or if a PLC is locking the machine, there will be no movement even though the relay pulls in correctly; in that case move on to the scenario where the relay pulls in and the motor does not turn. If the fault is not constant but intermittent, the cause is usually a loose connection or interference; treat the intermittent response fault separately. Where the limit switch is wired also determines which layer cuts the movement.
When you measure, make sure the machine movement is safe and, where necessary, that the load has been lowered. Write the result you find into the maintenance book; if the same fault recurs, the sequence does not start from the beginning again.
The full topic: Wireless Crane Remote Control Selection Guide