List of frequently asked questions
JDN Air Hoists work at a nominal pressure of 6 bar (85 psi). The hoists are designed in such a way that the full load can be lifted at 5,4 bar (76,5 psi) that a possible loss at the hose is compensated. On request special version for 4 bar (58,02 psi) are available.
JDN Air Hoists and cranes are – contrary to electrically operated – suitable for application in hazardous areas as the driving medium air opposite to electricity does not produce any sparks.
Explosion Protection Classifications on request.
JDN Air Hoists are working with air as supply medium. The air at a working pressure of appr. 6 bar (85 psi) is expanded in the motor. The expansion of air leads to a decrease of the air temperature, which cools the motor. On the latest generation of the PROFI and mini series the air flows through channels within the gear box and so also the gear train is cooled.
Due to this feature there is no down time and the rating is 100% duty cycle instead of electric hoists.
There is no limitation in starts/stops per hour.
Air hoists are insensitive with respect to high and low temperatures (70°C at motor, 150°C on chain and hook).
JDN Air Hoists PROFI comply the machine directive and therefore have an overload protection on all products with SWL´s starting from 1000 kg. The sophisticated control ensures that in case of overload the hoist stops. To unlock the stopped hoist, it has to be lowered by the pendant control to release the latched overload device.
On electric equipment the compartment or case is classified according to IP or NEMA. For example means IP 68 a housing safe against dust ingress and submersible for a certain time acc. to manufactures specification.
An Air Hoists is an open system which is by nature sturdy and insensitive against dirty, aggressive and humid environment. The supply air blows out any ingress. So this makes the air hoist a unique and reliable tool in harsh environment and incomparable to electric hoists.
| Fault | Possible cause | Remedy |
| Lifting not possible | Overload protection has shut off | Lower hook briefly, limit load to permissible load carrying capacity, then lift again |
| Air pressure too low | Increase air pressure to the required value | |
| EMERGENCY STOP switch is pressed | When the danger has passed, release the EMERGENCY STOP switch | |
| Hand control is faulty | Have hand control repaired | |
| Only very slow lifting is possible | Brake does not release fully | Set air pressure to the relevant value, Check seal of brake piston and change seal if necessaryCheck the adjustment of the brake piston (see spare-parts-list) |
| Brake lining worn or uneven | Replace brake lining | |
| Motor cover bolts loose | Tighten bolts | |
| Air supply hoses are leaking or loose | Check connections of air supply hose and control hoses and connect properly | |
| Cross section of air line too small | Use air line with sufficiently large diameter (check air pressure) | |
| Dirt in the service unit *Filter blocked |
Clean the service unit, ensure better air quality | |
| Silencer is clogged | Replace the silencer elements or clean, improve air quality if necessary | |
| Motor vanes worn | Replace motor vanes | |
| Motor has run dry | Lubricate motor, Check oiler* | |
| Control valve on motor | Have the control valve repaired | |
| Excessive running on during braking | Brake disc and/or brake piston | Replace brake disc and/or brake piston |
| Loud chain noise at chain sprocket | Chain dry Chain worn |
Lubricate chain Replace chain with new JDN chain |
| Chain sprocket worn | Replace chain sprocket, check chain guide, replace if necessary | |
| Wrong chain drawn in | Identify chain and replace with JDN chain if necessary | |
| Lifting or lowering speed reduced at higher lifting heights or motor comes to a standstill | Adjustment of brake piston too tight | Correct adjustment of brake piston. At high ambient temperatures perform adjustment with the device warmed up accordingly |
The mini widens the range of application in the light duty sector as a handy, flexible and universally deployable hoist making it an ideal tool for the most different handicraft workshops.
Carrying capacities: 125 kg up to 980 kg
JDN Air Hoists PROFI Series are very robust and therefore suitable for tough industrial applications even in continuous working processes. According to requirement there are various control systems. For traversing loads there are different trolleys to meet your special demands.
Carrying capacities: 250 kg up to 100 t
JDN Air Hoists M series are designed for operating in mines.
Take the according spare part list of your product and find the assembly for which the spare is required. On the bottom left of the page you will find a spare part drawing number. Inside the spare part drawing chapter you will find the referenced drawing helping you to identify the required spare part.
The table gives you a short overview acc. to ATEX. Please refer to your operation manual and relevant standards for more information.
Both, Division and Zone System classify areas based on:
| Comparison of area classification | |
| Division | Zone |
| Division 1: Where ignitable concentrations of flammable gases, vapours or liquids can exist all of the time or some of the time under normal operating conditions |
Zone 0: Where ignitable concentrations of flammable gases, vapours or liquids can exist all of the time or for long periods of time under normal operating conditions. Zone 1: Where ignitable concentrations of flammable gases, vapours or liquids can exist some of the time under normal operating conditions. |
| Division 2: Where ignitable concentrations of flammable gases, vapours or liquids are not likely to exist under normal operating conditions. |
Zone 2: Where ignitable concentrations of flammable gases, vapours or liquids are not likely to exist under normal operating conditions. |
| Comparison of ignition related properties of the explosive gas atmosphere: | |
| Division 1 and 2 | Zone 0, 1, 2 |
| A (acetylene) | IIC (acythelene & hydrogen) |
| B (hydrogen) | |
| C (ethylene) | IIB (ethylene) |
| D (propane) | IIA (propane) |
All hoists are marked with the EX-Markings acc. to the ATEX standard.
Acc. to ATEX every operator of a plant has to classify the hazardous areas of the plant into ZonesThe image illustrates simplified the zones of explosives atmospheres:
Zone 0
Permanent explosive atmosphere
Zone 1
Zone 1 hazardous area is classified as an area where an explosive atmosphere is likely to occur during normal operation. These conditions would be expected to be present for between 10 and 1000 hours per year.
Zone 2
In zone 2 hazardous area an explosive gas is not likely to occur during normal operation but if it should occur for some reason it would only exist for a short time. A potentially explosive atmosphere will occur for less than 10 hours per year.
Safe Area
Non hazardous area, no explosive atmosphere.
For correct handling of your spare part order the part number of the according spare part list is required. For us it is quite helpful to have the serial number of the hoist mentioned on the nameplate.
If your question is not answered within the FAQ chapter please contact JDN or our local representative.
As we are trying to update this information for your further assistance kindly let us have your feedback at info@jdn.de enabling us to improve our FAQ chapter.
Your JD NEUHAUS Team
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