Wohler DH 420 Compressed Air or Water Viper User Manual

Wohler DH 420 Compressed Air or Water Viper

General

Operation Manual Information

This operation manual allows you to safely work with the Wöhler DH 420 Pneumatic Viper. Please keep this manual for your information.
The Wöhler DH 420 Pneumatic Viper should be employed by professionals for its intended use only.
Liability is void for any damages caused by not following this manual.

Notes

WARNING! Not following this warning can cause injury or death.

ATTENTION!
Not following this note can cause permanent damage to the device.

NOTE! Useful information

Proper use

The Wöhler DH 420 Pneumatic Viper is equipped with a digital meter counter; it is designed to clean ventilation systems in conjunction with corre-sponding accessories and an air compressor.

When cleaning chimneys and ventilation systems lined with asbestos-based material the Wöhler DH 420 should be used in combination with the spe-cial sweeping unit for asbestos (see accessories) using water instead of compressed air. In such cases, the operating manual for the asbestos sweeping unit describes in detail the connections and how to use the unit.

Any other use is considered improper use.

Scope of supply

Wöhler

DH 420

| Pneumatic viper and integrated

digital meter counter

Compressed air hose with FRP

core, 10 m, with stop valve and coupling

Transport

Fig. 18: Lever in vertical position – transport lock

Fig. 19: Lever in horizontal position – working position

CAUTION!
It is essential to activate the transport lock prior to transport!

• Turn the lever located on the right next to the display downward.

The transport lock is now activated and the compressed air hose cannot be pulled out of the vipe.

CAUTION!
Release the transport lock before pulling out the hose!

• Before using the viper, turn the lever located on the right next to the display to a vertical position.

The transport lock is now deactivated and the compressed air hose can be pulled out of the viper.

Information on disposal

Electronic equipment does not belong into domes-tic waste, but must be disposed in accordance with the applicable statutory provisions.
You may hand in any defective batteries taken out of the unit to our company as well as to recycling places of public disposal systems or to selling points of new batteries or storage batteries.

Manufacturer

Wöhler Technik GmbH
Wöhler-Platz 1
33181 Bad Wünnenberg
Tel.: +49 2953 73-100
Fax: +49 2953 73-96100
E-Mail: [email protected]

Technical data

• Pneumatic viper
• Compressed air hose
• Viper cage
• Digital meter counter
• Compressor to be connected must fulfill the following requirements

Design and function

Fig. 20: Device components

Legend

1. Compressed air hose
2. Viper cage
3. Belt clip
4. Hose feed guide
5. Handle
6. Transport lock
7. Display
8. Star knob to adjust freewheel brake

Design and function

Fig. 21: Rear of device

1. Compressed air connection for compressor or hose reel

2. Stop valve for compressed air
   CAUTION!
   Valve set to direction of flow (see Abb. 4): Opened
   Valve set at right angles to direction of flow: Closed

3. Quick-release coupling for compressed air hose of viper.

Function

Fig. 22: Application example: Cleaning ventilation ducts

With the Wöhler DG 420 Pneumatic Viper it is possible to clean both rectangular and round ventilation ducts with large or small tube cross- sections.
You can hold the lightweight viper by the handle as you work or attach the clip to your belt so both of your hands are free to work with.
Thanks to its FRP reinforcement the 10 m long hose can easily be pushed into the ductwork.
The position of the end of the hose in the duct can be read off from the large display (digital meter counter).

Fig. 23: Hose reel – compressed air
Fig. 24: Helicopter nozzle and com-pressed air whip

With a 20 m hose the Wöhler hose reel is connected between the compressor and the com-pressed air viper to enable the user to move around freely while working without having to move the compressor.

It is possible to insert a compressed air whip or helicopter nozzle (forwards or backwards) onto the end of the hose to perform the cleaning task effectively.

Fig. 25: Roller guide ball 
The roller guide ball is deployed in wide, rectangular shafts, see accessories.

Layout of display and control button

Fig. 26: Display and control button

Description

1. Battery status
2. Length extended
3. Unit (meters or feet)
4. Retract (▼) or extend (▲) hose 5 Control button:
   Switch on, reset to zero, select unit

Preparing for use

Setting the freewheel brake

The freewheel brake makes it possible to wind the compressed air hose forward or back in a con-trolled manner. It prevents the hose unwinding off of the viper by itself.

The freewheel brake is set using the star knob located on the left of the display.

NOTE!
The freewheel brake is set ex works; generally speaking, it does not need to be adjusted.

Fig. 27: Star knob to adjust freewheel brake

To increase the braking effect

• Turn the star knob clockwise.
  The hose will now no longer run so easily out of the cage.

To decrease the braking effect

• Turn the star knob counterclockwise.
  You will now be able to pull the hose more easily out of the cage.

Connecting accessories

The end of the hose is fitted with a quick-release coupling for compressed air.

Attaching accessories

• Simply insert the Wöhler compressed air whip or the helicopter nozzle onto the quick-release coupling of the compressed air hose. Depend-ing on the task at hand, fit the roller guide ball between the hose and the compressed air whip/nozzle.
• To release the quick-release coupling simply grip and pull back the top sleeve.

Removing accessories

Fig. 28: Releasing the quick-release coupling

Connecting the hose reel and/or compressor

1. Compressed air connection
2. Stop valve for compressed air

CAUTION! Valve set to direction of flow (see Fig.): Opened Valve set at right angles to direction of flow: Closed

Fig. 29: Rear of device

Insert the connecting piece of the compressor, the extension hose or the compressed air viper onto the compressed air connection (1), Abb. 12: Gerä- terückseite

Operating

Switching the digital meter counter on / off

• To switch the digital meter counter on and off press and hold the control button for approx. 2 seconds.

When switched on the battery status, the length the hose is extended, the direction the hose was last moved (▲ extend or ▼ retract) as well as the unit of measurement used to display the length are shown on the display.

Fig. 30: Display with control button

NOTE!
The digital meter counter switches off automatically after 3 minutes if neither the hose is moved nor the control button is pressed on the viper. When it is switched on again the position 0.0 is displayed.

Selecting the unit of measurement

It is possible to choose between the units of measurement meters (m) and feet (ft). The last unit selected is always displayed when the device is switched on.

• To change the unit of measurement you must first switch off the device.
• Press and hold the control button for approx. 10 seconds until the new unit is shown in the display.

Zeroing

• To reset the extended length measurement to 0.0 press the control button briefly.

NOTE!
To ensure you are able to read precisely the length the hose is extended into the duct, we recommend you zero the display when the beginning of the hose is inserted into the duct.

Winding the hose forward and back

• Release the transport lock (see paragraph 1.5).
• Carefully pull the hose out of the viper cage.

CAUTION!
When pushing the hose back onto the viper make sure the hose is wound evenly across the width of the viper cage. Otherwise, the hose can spring out of the viper cage under certain circumstances, if it is wound predominantly onto one side.
WARNING!
Be cautious when handling the hose: The compressed air hose is reinforced with a FRP core; due to the inherent spring force it can whip to one side in a similar fashion to a rod.

Cleaning with compressed air

Fig. 31: Stop valve for compressed air opened

WARNING!
Check all connections before switching on the supply of compressed air.
Make sure all stop valves are closed before switching on the compressor.

• Switch on the compressor in accordance with the manufacturer’s instructions, then open the red stop valve for compressed air.

CAUTION!
Valve set to direction of flow (see Abb. 14: Absperrhahn Druckluft geöffnet): Opened Valve set at right angles to direction of flow: Closed

You can now begin with cleaning.

WARNING!
Never touch nozzles or compressed air whips with your hands when the compressor is switched on.

Recommendations for cleaning with compressed air

Fig. 32: Procedure for cleaning ventilation shafts

Sealing openings

Ductwork of ventilation systems consist of a main duct and a variety of branch ducts. The cleaning process is carried out employing negative air pres-sure; in other words, through suction extracting detached particles of dirt with a dust collector. Be-fore beginning with cleaning you must ensure all open, unused branch ducts and bypass ducts are sealed; close any volume control dampers. Use sealing bladders for the purpose (see accessories).

Cleaning

The ducts are cleaned with compressed air working from the cleaning opening to the extractor
(Wöhler dust collector SF 250). A stream of pressurized air from the compressor blows the dust from the walls of the ducts/shafts via the com- pressed air whips or nozzles.

The roller guide ball is used to clean shafts with wide corners. It is possible to steer the hose in all directions and into all corners with controlling hand movements.
Fig. 33: Cleaning ductwork with a roller guide ball and compressed air whip, dirt extracted with dust collector

Maintenance

The Wöhler Pneumatic Viper DH 420 is rugged by design so it only very rarely needs maintenance.

Maintenance list

Replace hose

• Unwind the hose to be replaced completely and release the quick-release coupling.

WARNING!
Exercise due care and attention when pulling out the hose: The last winding could be under tension and cause the hose to make a whipping movement

• Insert the replacement hose in the quick-release coupling and wind the hose evenly on-to the viper.

Replace battery

Fig. 34: Replace battery

The digital meter counter is fitted with a long-life battery that only needs to be replaced every 5-10 years. The battery status is shown by the battery status indicator in the display. To replace the battery proceed as follows:

• Pull the frame away from the display.
• Carefully grip the display and pull it out along with the PCB and battery.
• Remove the battery from the rear of the PBC and connect a new 3.6 V lithium battery.
• Place the display along with the PCB and battery back in the original position.
• Put the frame of the display back in its position and press it securely into place.

Warranty and Service

Warranty

Each Wöhler DH 420 will be tested in all functions and will leave our factory only after extensive quality control testing. The final control will be recorded in detail in a test report and delivered with any unit.
If used properly, the warranty period for the Wöh-ler DH 420 will be 12 month from the date of sale. The hose is not covered by this warranty, because it is a consumable.
This warranty does not cover the freight and pack-ing costs when the device is sent to the factory for repair.
Wöhler has built our reputation on excellence in customer service. Therefore, of course, we are readily available to assist you after the warranty period ends.

Service

• Send us the device and we will repair it and return it to you with our package service.
• Immediate help is provided by our technical staff over the telephone.

Declaration of conformity

The manufacturer
WÖHLER Technik GmbH
Wöhler-Platz 1, D-33181 Bad Wünnenberg declares that the product

Product: Wöhler Pneumatic Vipe
Model: DH 420

complies with the key safety requirements set down in the guidelines of the Council for the Harmonization of the Legal Requirements of the Member States in relation to the electromagnetic compatibility (2014/30/EU).

The following standards were availed of to evaluate the product in respect of the electromagnetic compatibility:

• DIN EN 61326-1, table 2 and 3
• DIN EN 61326-1, table 2 and 3
• DIN EN 61326-1, table 2
• DIN EN 55011 class B group 1

Bad Wünnenberg, 04.08.2022

Dr. Stephan Ester, Geschäftsführer/Managing Director

References

• Wöhler France SARL
• Wohler USA Inc.

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