Question 1

How many channels should a crane remote control have?

Accepted Answer

The channel count equals the number of independent movements. Typically 2 for a fixed hoist, 4 for a crane travelling on a rail, and 6 for an overhead crane. Up/down works bidirectionally on a single channel.

Question 2

Why is the crane remote control range lower than the catalogue value?

Accepted Answer

The catalogue value is measured in an open, unobstructed area. The most frequent cause is the receiver antenna being left inside a metal panel; moving the antenna outside the panel solves the problem in most cases.

Question 3

What amperage model should I choose for a DC motor driver?

Accepted Answer

The driver current should be chosen as at least 1.5 times the motor's continuous running current. The instantaneous current at start-up can rise to 3–5 times the continuous current; not leaving this margin shortens the driver's life.

Question 4

Why is PWM speed control better than dropping the voltage?

Accepted Answer

Instead of cutting the voltage, PWM sets the average power by switching the full voltage on and off quickly. The heat loss on the driver is far lower and the motor keeps its torque at low speed.

Question 5

Which tractor models does the lift retrofit kit fit?

Accepted Answer

Retrofit kits fit according to the mechanical structure of the hydraulic lever, not the tractor brand. On most Lift-O-Matic and similar systems operated by a manual lever, installation can be done without removing the lever.

Question 6

What is the difference between proportional control and on/off control?

Accepted Answer

On/off control opens or closes the valve fully; movement starts abruptly and stops abruptly. In proportional control the amount of joystick movement is converted into speed, and the load is positioned precisely without being shaken.

Question 7

How is the speed of three pumps synchronised on a drilling rig?

Accepted Answer

An independent servo actuator and potentiometer is used for each pump. The operator sets the three speeds separately from a single cabin; because there is no mechanical linkage, one does not affect the other.

Question 8

Why is RV levelling necessary?

Accepted Answer

A fridge's cooling cycle works in the horizontal position; on a slope its efficiency drops and it can be damaged. Doors also close by themselves, water drainage is disrupted and sleep comfort drops noticeably.

Question 9

What is the difference between ST100 and SF100, and which should I choose?

Accepted Answer

The receiver of ST100 and SF100 is the same: LF100R, panel-mount, 2x10A relay output, 12/24V DC or 220V AC supply. The difference is in the remote control and in the range. ST100 has the LT200 Li-Po rechargeable IP67 remote control and approximately 150 m open-field range, while SF100 has the LF200 3xAAA battery-powered IP64 remote control and approximately 100 m range.

Question 10

Is the receiver the only difference between the ST100 and the ST200?

Accepted Answer

Yes, the decisive difference is the receiver. In both sets the remote control is Li-Po rechargeable and IP67, the range in open areas is approximately 150 m, and the charging input is an AXI-Link 3-pin connector. The ST100's receiver is the LF100R panel-mount type (2x10A on 2 channels, 12/24V DC or 220V AC); the ST200's receiver is an IP67 outdoor type in a sealed enclosure.

Question 11

What is the difference between SF100 and SF200?

Accepted Answer

The remote control is the same on both sets: LF200, 3xAAA battery-powered, IP64 protected, with a range of approximately 100 m in open field. The difference is in the receiver. The SF100's receiver is the panel-mount type LF100R, gives a 2x10A relay output and is supplied with 12/24V DC or 220V AC. The SF200's receiver is the LT200R: IP67 outdoor, with cable glands, a gasketed cover and a 12/24V DC supply.

Question 12

Should I prefer a rechargeable remote control or a battery-powered one?

Accepted Answer

In the ST series the LT200 remote control is Li-Po rechargeable and IP67 protected; in the SF series the LF200 remote control runs on 3xAAA batteries and is IP64 protected. The rechargeable model is advantageous in terms of consumable cost and shift continuity, while the battery-powered model is advantageous in that a flat battery can be replaced within seconds. The decision depends on whether you can establish charging discipline on site.

Question 13

How do I decide between a panel-mount receiver and an IP67 outdoor receiver?

Accepted Answer

The decision is determined by the physical location of the receiver. If a protected electrical panel already exists, the panel-mount LF100R is enough; in the 2-channel version it offers a 2x10A relay output and a 12/24V DC or 220V AC supply. If the receiver will sit outdoors or on the machine body, an IP67 outdoor receiver is required (LT200R on SF200, IP67 housing on ST200). IP67 refers to an immersion test; resistance to water jets is a separate rating.

Question 14

In which cases do I need to buy 4 channels instead of 2?

Accepted Answer

2 channels control the forward and reverse direction of a single movement. When a second independent movement is required you move up to 4 channels: on a twin-motor platform CH1-CH2 drives the first motor and CH3-CH4 the second. Crane hoisting plus boom movement, a gate plus a barrier, and actuator control on the X and Y axes are typical 4-channel scenarios.

Question 15

In which applications is a 6-channel set needed?

Accepted Answer

Six channels are chosen when three independent bidirectional movements have to be managed from a single remote control. Hoisting, boom and slewing on a port crane; three-axis platform positioning; a door plus a lock mechanism; separate control of pumps A, B and C are typical examples. The 6-channel option is offered in the ST200 series.

Question 16

What comes out of the box in a crane remote control set?

Accepted Answer

The SF100 set contains the LF200 remote control, the LF100R panel-mount receiver, an antenna, a wiring diagram and a user manual. The SF200 set comes with the LF200 remote control, the LT200R IP67 receiver, an antenna and cable glands, a diagram and a manual. The ST series includes the Li-Po rechargeable LT200 remote control and the AXI-Link 3-pin charging connector.

Question 17

Which applications is a range of roughly 100 m enough for?

Accepted Answer

The roughly 100 m open-area range of the SF100 and SF200 covers most applications where the operator uses the machine within sight: in-shop hoists, service lifts, bucket loading, doors and barriers, fixed cranes. This figure is an open-area value; concrete walls, steel structures and inverter interference noticeably reduce the real distance.

Question 18

Is a set with 150 m range unnecessary for use inside a workshop?

Accepted Answer

No, it is not unnecessary. Because concrete walls, steel columns and machine bodies weaken the signal in an enclosed workshop, a set that gives roughly 150 m in the open provides a comfortable working margin in a 40-50 m workshop. Excess range is not a luxury but the reserve set aside for connection stability in an obstructed environment.

Question 19

In what order should I evaluate the criteria when choosing a crane remote control?

Accepted Answer

Evaluate the following seven headings in order: channel requirement, the receiver's mounting location and protection requirement, the actual working distance, receiver supply voltage, load type and contactor requirement, remote control power preference (Li-Po rechargeable or 3xAAA batteries), ambient conditions and the maintenance plan. This order eliminates the risk of having to change the receiver later.

Question 20

Can I run two separate machines with the same remote control?

Accepted Answer

One remote control driving more than one machine can be considered in two different ways: distributing the different channels of a single receiver between two machines, or teaching the same remote control to two separate receivers. The first way can be applied directly with 4- or 6-channel sets. The second way depends on the set's teaching procedure and must be confirmed before purchase.

Question 21

Can I switch to wireless control without removing my existing pushbutton wiring?

Accepted Answer

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.

Question 22

Can a crane remote control set be used for sliding gates and barriers?

Accepted Answer

Yes. Because the output is a relay contact, the same set is also used on gate and barrier motors. The product data defines a gate plus barrier 4-channel scenario and a gate plus lock 6-channel scenario. If the gate motor runs on mains voltage, an in-panel receiver is preferred; if it will stay outdoors on the gate post, an IP67 outdoor receiver is preferred.

Question 23

How should I mount the receiver in the panel?

Accepted Answer

Mount the in-panel receiver as far as possible from the inverter, contactors and motor cables, preferably on the signal side of the panel. Leave at least about 20 cm between power and control cables, cross them at right angles where crossings are unavoidable, and bring the antenna outside the panel in a vertical position. If the antenna stays inside the metal panel the range drops severely.

Question 24

Should I supply the receiver with 12V DC or 220V AC?

Accepted Answer

The LF100R receiver can be supplied with 12/24V DC or 220V AC; this flexibility applies to the ST100 and SF100 sets. For the SF200's LT200R receiver, 12/24V DC is stated. If a 24V DC control voltage is already available in your panel, DC supply is safer; if you only have mains, the 220V AC option removes the need for an additional power supply.

Question 25

Where should I place the antenna?

Accepted Answer

Bring the antenna outside the metal panel, fix it in a vertical position and keep it a few centimetres away from large metal surfaces. Move it as far as possible from interference sources such as motor cables, inverters and welding machines. Most range losses stem not from distance but from faulty antenna placement.

Question 26

Does shortening or extending the antenna cable affect the range?

Accepted Answer

Yes, adversely. An antenna and its cable are designed for a particular impedance and length match; cutting it shorter or splicing it longer spoils that match, the reflected power increases and the radiated power drops. Instead of coiling up slack cable, arrange it in wide loops, and if an extension is needed use a manufacturer-approved extension kit.

Question 27

What happens if the receiver antenna stays inside the panel?

Accepted Answer

A metal panel behaves like a Faraday cage and largely absorbs the radio signal. If the antenna stays inside the panel the range can drop to a level measured in metres, commands are received intermittently and the source of the fault is assumed to be the product. The solution is to bring the antenna outside the panel, in a vertical position and a few centimetres away from metal surfaces.

Question 28

Should I connect the relay output directly to the motor or to a contactor?

Accepted Answer

On small DC motors, the LF100R's 2x10A relay output has the capacity to handle forward/reverse direction control without a contactor. On large motors, however, the correct method is to drive the contactor coil with the relay contact and let the contactor carry the motor current. This approach protects the relay contact, makes the part to be replaced in the event of a fault cheaper, and makes it possible to add thermal protection.

Question 29

Why is electrical interlocking between forward and reverse contactors mandatory?

Accepted Answer

If the forward and reverse contactors pull in at the same time, the motor supply phases are short circuited to each other; the result is welded contacts, blown fuses and a fire risk. To prevent this, the normally closed auxiliary contact of each contactor is wired in series with the coil circuit of the other, and a mechanical interlock is added as well.

Question 30

Is a snubber or a diode needed to extend the life of the relay contact?

Accepted Answer

Yes, it is necessary on inductive loads. The high voltage that arises when an inductive load such as a contactor coil is interrupted produces an arc and burns the relay contact. Using a freewheeling diode connected in reverse parallel with the coil on DC coils, and an RC snubber on AC coils, suppresses the arc energy and noticeably extends contact life.

Question 31

How many kW of motor can I drive with a 10 A relay output?

Accepted Answer

It would not be correct to give a single kW figure, because the ampere rating given for a relay contact generally applies to a resistive load condition. On inductive loads such as motors the starting current rises to roughly 10 times the running current, and the contact rating is calculated with a substantial reduction. With large motors the correct method is to drive a contactor coil with the relay.

Question 32

Why should I derate the relay current rating on an inductive load?

Accepted Answer

Because the ampere figure in the catalogue is mostly measured under resistive load (AC-1) conditions. With inductive loads such as contactor coils, solenoids and motors there is both a start-up current of about 10 times the running value and an arc at the moment of breaking. For this reason the common practice is to apply a significant derating, and even to use only 20-40 percent of the resistive rating.

Question 33

How does a cable gland preserve IP67 protection, and what happens if it is fitted wrong?

Accepted Answer

On receivers with an IP67 enclosure, protection depends on choosing a cable gland that matches the cable diameter and tightening it fully. If the gland stays loose, if it is oversized for the cable, or if an unused hole is not closed with a blanking plug, water and moisture get into the enclosure. The IP67 class means 30 minutes of immersion at 1 m depth per IEC 60529, and it only holds with correct installation.

Question 34

Is it correct to mount the receiver right next to the motor?

Accepted Answer

Although it looks attractive because the cable gets shorter, the area right next to the motor and the motor cable is the worst zone in terms of interference. The motor cable and the inverter output radiate broadband electromagnetic noise. Move the receiver, and especially the antenna, away from this zone; leave at least about 20 cm between power and signal cables.

Question 35

Should I wire the limit switch to the remote control or to the contactor?

Accepted Answer

A limit switch must always be wired in series into the power circuit, that is, into the contactor coil line. The order is: receiver relay output, then the normally closed contact of the limit switch, then the contactor coil. That way limit protection works independently of the radio link and of the receiver's state; when the limit switch opens, the contactor cannot pull in under any circumstances.

Question 36

Should I fit a separate fuse on the receiver supply?

Accepted Answer

Yes. Fitting a separate fuse or miniature circuit breaker of suitable rating in the receiver supply line is standard good practice. That way only the control line is isolated in a short circuit, the fault point is found quickly, and the receiver's power can be safely cut from a single point during servicing. Confirm from the user manual whether the receiver has an internal fuse.

Question 37

How do I pair the remote control to the receiver?

Accepted Answer

Pairing is done according to the learning procedure described in the user manual: the receiver is put into learning mode and, by sending a command from the remote control, the remote control's ID code is stored in the receiver. Sets may come factory paired; if the set works out of the box, you do not need to run the learning procedure. Always apply the step details from your own set's manual.

Question 38

What should I do if the pairing is lost?

Accepted Answer

First confirm that it really is a pairing problem: check the remote's battery/charge, the receiver supply, the fuse and the antenna connection. If those are sound, apply the teach-in procedure in the user manual again. Carry out the operation with the power circuit disconnected and at close range to the receiver, then verify each channel one by one.

Question 39

Can two different remote controls on the same site trigger each other?

Accepted Answer

What prevents a clash is not the frequency being different but each transmitter-receiver pair being paired with its own identity/address code. Devices sharing the same band do not accept each other's code. However, if a large number of devices in the same band transmit simultaneously, the range and response time may drop; this is not a clash but channel occupancy.

Question 40

Can more than one remote control be paired to a single receiver?

Accepted Answer

How many transmitters can be paired to a receiver depends on the set's learning logic, and no number is stated in the product data. So if you are planning a spare remote control or two-operator use, confirm the capacity from the user manual or technical support before purchase. Functionally, the correct arrangement is for only one operator to give commands at a time.

Question 41

Can one remote control drive more than one receiver?

Accepted Answer

Whether this is possible depends on the set's learning logic and is not stated in the product data; confirm with technical support before ordering. The alternative, directly applicable method is to share out the channels of a single receiver: on a 4-channel set CH1-CH2 drives the first mechanism and CH3-CH4 the second.

Question 42

Does it make sense to buy a spare remote control, and will it work with the same receiver?

Accepted Answer

In facilities where production depends on the remote control, keeping a spare reduces downtime from days to minutes. For the spare device to work with the same receiver, it has to be taught according to the teaching procedure in the user manual; since the number of transmitters that can be taught to one receiver is not stated in the product data, confirm this before purchase.

Question 43

If I lose the remote control, how do I secure the receiver?

Accepted Answer

The first step is to cut power to the machine or remove the receiver supply fuse; that way no movement can occur even if the lost remote control comes back into range. Then re-pair the receiver with a new remote control following the learning procedure in the user manual. Confirm with technical support whether the operation disables the lost device.

Question 44

How should I distribute channel numbers across the motors?

Accepted Answer

Every direction of movement consumes one relay contact; a single motor moving forward and reverse needs 2 channels. On a 4-channel set, CH1-CH2 is mapped to the forward-reverse direction of the first motor and CH3-CH4 to the forward-reverse direction of the second motor. On a 6-channel set, the same logic puts a third axis of movement on CH5-CH6. Do the distribution on paper before wiring.

Question 45

How many channels does a two-speed (two-step) crane consume?

Accepted Answer

On a two-speed motor, low speed and high speed mean separate windings/contactors. If you want to drive the forward-reverse motion in two steps you need 4 relay outputs: forward-slow, forward-fast, reverse-slow, reverse-fast. So two speeds on a single axis turn a 2-channel job into a 4-channel one.

Question 46

Can I increase the number of channels later?

Accepted Answer

The channel count is fixed by the number of relay outputs on the receiver and by the button layout of the remote control; it cannot be expanded by software or by a setting. If the need grows, you move to a set with more channels. On the AXI side, the ST100 comes in 2 and 4 channels, the ST200 in 2, 4 and 6 channel options; the SF100 and SF200 are 2 channels.

Question 47

Is an emergency stop given over the wireless remote control enough?

Accepted Answer

No. In the general approach to machine safety, a stop command sent over a wireless link does not automatically replace the fixed, hard-wired emergency stop device on the machine in the sense of ISO 13850. The machine is also expected to have a manually reset, latching red mushroom-head button; wireless stopping complements it, it does not substitute for it.

Question 48

What is the difference between a passive stop and an active stop?

Accepted Answer

A passive stop is the stop that occurs by itself when the transmitter's broadcast is interrupted (battery flat, device switched off, out of range). An active stop is the automatic stop the base station initiates itself upon not detecting a valid signal; the time depends on the manufacturer's declaration and on the risk assessment for the machine, and is expected not to exceed approximately 0.5 seconds.

Question 49

What does the crane do if the remote control's battery goes flat?

Accepted Answer

On wireless remote control systems the expected general behaviour is that when the transmitter's broadcast is interrupted the receiver releases its relay outputs and the movement stops; this is called a passive stop. A command staying latched is not acceptable behaviour. Confirm this behaviour for your set from the user manual.

Question 50

Does the movement stop if the remote control goes out of range?

Accepted Answer

Yes, this is the expected general behaviour: when the receiver does not get a valid signal it releases its relay outputs and the movement stops. As you approach the range limit the response first becomes intermittent, then breaks off completely. The ranges declared for AXI sets are open-field values: SF series ~100 m, ST series ~150 m.

Question 51

What should the watchdog (communication monitoring) time be?

Accepted Answer

On wireless remote controls the receiver waits for a valid signal to be refreshed within a time window; if the window expires, a stop is initiated. This time is not a fixed regulatory figure: the manufacturer declares it, the risk assessment on the machine determines it, and in wireless remote control applications it is expected not to exceed approximately 0.5 seconds.

Question 52

What is the difference between stop category 0 and category 1?

Accepted Answer

In IEC 60204-1, Category 0 is an uncontrolled stop produced by removing power immediately. Category 1 first decelerates in a controlled manner and removes power after the machine has stopped. Category 2 stops in a controlled manner but keeps power on. An emergency stop function can only be Category 0 or 1; Category 2 cannot be used as an emergency stop.

Question 53

What does IEC 62745 require for wireless remote controls?

Accepted Answer

IEC/EN 62745:2017 (+A11:2020) is a Type-B2 standard defining the requirements for wireless control systems of machinery; it covers in particular portable control stations carried by the operator. It is applied in addition to IEC 60204-1. It does not specify the communication protocol, the frequency band, or EMC and IP protection requirements.

Question 54

What does the EN 13557 crane control standard cover?

Accepted Answer

EN 13557 (current edition BS EN 13557:2024, Cranes - Control devices and control stations) sets the health and safety design requirements for control devices and control stations for every type of crane. Levers, joysticks, buttons, pedals, touch interfaces and their layout are within scope; from a fixed cabin to a remote control station.

Question 55

What electrical requirements does EN 60204-32 set for lifting machines?

Accepted Answer

EN IEC 60204-32 deals with the electrical and electronic equipment of lifting machines up to 1000 V AC / 1500 V DC and at frequencies not exceeding 200 Hz. The scope starts at the supply disconnector; overhead, tower, mobile, portal and floating cranes, hoists, monorails and storage and retrieval systems are included.

Question 56

What do PL d and Category 3 mean in ISO 13849?

Accepted Answer

EN ISO 13849-1 classifies the safety-related parts of control systems with Performance Levels (PL) from a to e and Categories B, 1, 2, 3, 4. Category 3 requires that a single fault does not cause the loss of the safety function; PL d is a high level of risk reduction. For the radio-controlled stop function of a crane, the target commonly used in the sector is Category 3 / PL d.

Question 57

If the power is cut, does the remote control command stay latched?

Accepted Answer

It must not. When the supply is cut the receiver's relays drop out, the contactors release and the motion ends. So that the machine does not start by itself when power returns, a self-holding (sealing) circuit or a restart interlock with a phase protection relay must be built on the panel side.

Question 58

How is unintended operation prevented on a wireless remote control?

Accepted Answer

Prevention of unintended operation is one of the headings IEC/EN 62745 addresses explicitly. Four layers are used in practice: pairing each transmitter-receiver pair with a unique identity code, serial data integrity and error detection, the command not passing automatically when the device is switched on, and two-handed or enabling-button operation for critical motions.

Question 59

What is the difference between the 433 MHz and 868 MHz bands?

Accepted Answer

In the 433.050-434.790 MHz band the permitted power is 10 mW e.r.p. and, for systems without frequency hopping, the duty cycle is limited to 10%. In the 868 MHz sub-bands the power rises to 25 mW e.r.p. but the duty cycle drops to 1% or 0.1%. The lower frequency diffracts better behind obstacles, the higher frequency needs a shorter antenna.

Question 60

How does the duty cycle limit affect the remote control?

Accepted Answer

The duty cycle is the maximum proportion of time a device may stay transmitting within a given period. In the 433.050-434.790 MHz band the limit is 10% for systems without frequency hopping, and 1% or 0.1% in the 868 MHz sub-bands. The purpose of the limit is to stop devices sharing the band from drowning each other out.

Question 61

Does an inverter (frequency converter) interfere with the remote control?

Accepted Answer

Yes. The fast switching of inverters produces broadband common mode noise, and the motor cable behaves like an antenna radiating that noise. The most effective and cheapest measure is distance: move the receiver and its antenna away from the inverter and the motor cable, and leave at least about 20 cm between power and signal cables.

Question 62

The remote control drops out while the welding machine runs, what should I do?

Accepted Answer

The welding arc is one of the harshest field sources of broadband electromagnetic noise. The first response is distance: move the receiver antenna away from the welding area and the welding cables. Then take the receiver supply from a separate supply branch, fit ferrite rings on the control cables and check the earthing system.

Question 63

At which end should I earth the shield of a shielded cable?

Accepted Answer

The rule depends on the frequency of the noise. With high-frequency noise from an inverter (above 1 MHz) the shield is earthed at both ends; that is what is correct for the motor cable. With low-frequency noise and where there is a risk of an earth loop, earthing at one end is preferred. In both cases the shield must be connected with a 360 degree clamp.

Question 64

How much separation should I leave between control and power cables?

Accepted Answer

Leave at least about 20 cm (8 inches) between power cables and control/signal cables running in parallel. Make unavoidable crossings at a 90 degree right angle. Avoid carrying them in the same cable trunking; if the same trunking must be used, choose trunking with a metal divider.

Frequently Asked Questions