Installation Guide for M3J-EMM Rosahl Dehumidifier

For correct usage

– Please read this installation guide before installing the dehumidifier. Incorrect use will invalidate the warranty.

General Safety Warnings

• This product is for indoor use only in sealed display or storage enclosures.
• Installation requires the use of tools and technical skills. Not suitable for children or unqualified personnel.
• DO NOT use silicone based sealing materials or they will permanently damage the membrane
• Do not touch, damage, or modify the membrane in any way
• Only use this product with supplied or approved components. Do not substitute the power adapter or modify the membrane or housing. Do not allow the membrane to become wet
• Do not reverse or disconnect wiring, as this will permanently damage the dehumidifier membrane.
• The power adapter includes electronic components sensitive to electrostatic discharge (ESD). Only qualified personnel should remove or service it. –
• Do not use near rust inhibitors, vapour phase corrosion inhibitors or high-density organic gases as they will damage the membrane and reduce performance

Electrical Safety

• Power Input: 5V DC via USB-C (minimum 15W)
• Operating Voltage: 3V DC (regulated via internal adapter)
• The integrated VREG2 adapter includes fold-back current limiting for safe startup.
• Use only with a Class 2 power source or LPS (Limited Power Source) as defined in IEC 62368-1.
• The adapter is not a USB Power Delivery (PD) compliant sink device. Use a standard 5V USB-C power supply if issues occur.
• To disconnect power, simply remove the USB-C plug from the device or switch off the USB power adapter at the source

Environmental Conditions

• Operating temperature: -10°C to +50°C
• Storage temperature: -20°C to +60°C
• Humidity: 10–90% RH (non-condensing)
• Altitude: Up to 2000 m
• Not tested for outdoor use or exposure to liquids.

Maintenance and Servicing

• This product is maintenance-free and contains no user-serviceable parts.
• Do not open, modify, or attempt to clean the membrane or circuit board.
• If the device is damaged or fails to operate, contact the supplier for support or replacement.

Disposal and Recycling

• This product must not be disposed of with regular household waste.
• Dispose of this equipment in accordance with local electronic waste regulations.
• For European customers: This product is covered by the WEEE Directive. Return it to your supplier or designated collection point.

Overview and Installation

Dehumidifier Moulds

The M3J-EMM is a dehumidifier for mounting on the outside of an enclosure. Other mounting arrangements are also available. These membrane dehumidifiers are suitable for use with a wide range of sealed display and storage enclosures to protect sensitive and delicate equipment.
The main components are the moulds, a pre-wired power adapter board, the Rosahl membrane and two sealing rings.
When mounted on the outside of a sealed enclosure and connected to a USB-C power supply (not supplied), the dehumidifier expels moisture through the membrane. Installation requires a hole to be made in the enclosure wall through which the moisture is expelled. See below for instructions. The dehumidification process is silent, waterless, maintenance-free and has a low energy footprint.

CAUTION: it is important not to remove or reverse the electrical connections as this will damage the membrane. The dehumidifier membrane needs a 3V DC power source. It receives this from the integrated USB-C power adapter board which reduces the voltage from a standard 15-Watt USB power supply from 5 Volts to 3 Volts

Assembly & Mounting Instructions

You can mount the dehumidifier vertically or horizontally on the side of the enclosure but ensure the USB connection is in your chosen location.

1. Mounting Location

The mounting kit consists of:
– Inner fixture – holds the membrane and USB-C power adapter module.
– Outer cover – secures and protects the assembly.
– Back plate – optional for extra support on flexible enclosure walls.

2. Marking and Preparing the Cut-out

– Position loose backplate in the desired location and mark the screw holes.
– Drill one 3.5mm hole first, temporarily bolt the backplate in position. Check the other drill marks are correctly located and using a scribe tool mark the position of the cutout for the vent, then drill the remaining holes.
– Cut the rectangular vent opening using a suitable method. For example, using a  Rotary tool with a cutting disk, or manually by drilling a ring of small holes and filing the edges smooth (the installed dehumidifier will cover the cutout)
– Take care not to inhale fumes or dust from the cutting

3. Installing Components

Caution: Do not touch the black (internal) or grey (external) membrane surfaces. Wear gloves to prevent damage or contamination.

– Remove the nuts and washers but leave the four screws holding the inner fixtures together, but do not separate the moulds
– Correctly orientate the supplied gasket to the moulds and hold in position with the screws. Note that the fixing holes are offset
– Position the dehumidifier and push the fixing screws through the case and refit the washers and nuts. Do not over tighten the nuts.
– If the enclosure wall is thin or flexible, use the back plate inside the enclosure for a firm seal.

Notes

– Always use the sealing rings to prevent moisture leakage.
– Confirm that the gasket is fully compressed for an airtight seal.

Additional resources

–Additional resources at  https://micro-dehumidifier.com/documentation/
– Membrane dehumidifier user  manual RB-OP21004                             Open PDF
– Membrane RoHS Declaration of Conformity                                          Open PDF
– Membrane REACH Declaration of Conformity                                       Open PDF
– Dehumidifier UKCA/CE Declaration of Conformity                                Open PDF
– Power adapter board RoHS Declaration of Conformity                         Open PDF
– Power adapter board REACH Declaration of Conformity                      Open PDF

Westside-International Ltd

Boston House, Downsview Road, Wantage, Oxfordshire, OX12 9FF. UK

enquiries@micro-dehumidifier.com