Installation Guide for VR2 Mounting bases 

 Rosahl membrane electric dehumidifiers

The VREG2 Series power adapter boards offer a simple and convenient way to convert a 5V USB supply to a 3V DC current limiting output. They are suitable for the Rosahl micro-dehumidifier membranes PD, RD, RS, M-1J, M-2J, M-3M, M-3J and MDL-3.

To simplify the VREG2 installation, three mounting bases are avalaible to order:

The VR2-PMC is a simple 22mm barrel mounting module for the VREG2 USB-C power adapter board (order separately).

This simple VR2-FMC simple base-mounting module accepts the VREG2 USB-C power adapter board (order separately).

Installation Guide for VR2-PMC

VREG2 USB-C Power Adapter Board with VR2-PMC Barrel Housing

1. Components

The VR2-PMC barrel housing is purchased separately from the VREG2 adapter board. It consists of:

• Barrel housing (22 mm diameter)
• Internal locking ring (secures the VREG2 inside the barrel)
• External M22 locking ring (secures the assembly to the panel)

2. Cable Preparation

• Cut two 0.5mm (AWG 24) electrical cables to the required length.
• Solder cables to the VREG2 solder pads:

• Red cable → Positive (+) pad
• Black cable → Negative (–) pad

3. Board Insertion

• Orient the USB-C slot uppermost in the barrel moulding.
• Carefully slide the VREG2 board into the barrel using the guide slots.
• Press until the USB-C connector is flush with the front of the barrel.

4. Internal Locking Ring

• Pass the cables through the internal locking ring.
• Screw the ring into the rear of the barrel to secure the board.
• Apply a small amount of non-silicone sealant to the cable entry hole to reduce moisture ingress.

• ⚠️ Do not use silicone sealants — they permanently damage the membrane.

5. Cable Termination

• Fit cable crimps to the conductors.
• Ensure crimps are compatible with the membrane type.
• ⚠️ Note: M-Series membrane terminals use special alloys and are unsuitable for soldering.

6. Panel Installation

• Drill or prepare an 18.5 mm hole in the panel.
• Insert the barrel housing into the hole.
• Hand-tighten the external locking ring to secure the assembly.

Installation Guide for VR2-FMC

VREG2 USB-C Power Adapter Board with VR2-FMC Barrel Housing

1. Components

The VR2-FMC barrel housing is purchased separately from the VREG2 adapter board. It consists of:

• Flat mounting base and cover

2. Cable Preparation

• Cut two 0.5mm (AWG 24) electrical cables to the required length.
• Solder cables to the VREG2 solder pads:
• Red cable → Positive (+) pad
• Black cable → Negative (–) pad

3. Board Insertion

• Carefully position the VREG2 board into the base until flat.
• Ensure the USB-C connector is flush with the front of the barrel.
• Align cables with the exit slot at the end of the base.

4. Top Cover

• Taking care not to damage the cables press the top cover in place.
• Secure the top cover using the supplied M3 mounting screws.

5. Cable Termination

• Fit cable crimps to the conductors.
• Ensure crimps are compatible with the membrane type.
• The optional M-5PKT fixing kit includes terminal crimps for both M-Series and MDL-Series membranes

⚠️ Note: M-Series and MDL membrane terminals use special alloys that are unsuitable for soldering.

6. Panel Installation

• Drill or prepare two 3.5mm holes in the base plate.
• Fix in position using the M3 screws, nuts and washers supplied.

Installation Guide for VR2-RSM

VREG2 USB-C Power Adapter Board with VR2-RSM 35mm Barrel Housing

The VR2-RSM offers a compact mounting solution for the RS Series dehumidifier membranes. The 35mm barrel mounting holds both the dehumidifier and VREG power supply (order separately). It is a difficult assembly and is available fully assembled for ease of installation as the VR2X-RSM.

1. Components

The VR2-RSM barrel housing is purchased separately from the VREG2 adapter board. It consists of:

• Barrel housing (35 mm diameter)
• Internal locking segment (secures and seals the VREG2 inside the barrel)
• External locking ring (secures the assembly to the panel)

2. Cable Preparation

• Cut two 0.5mm (~AWG 24) electrical cables to the required length.
• Solder cables to the VREG2 solder pads:
• Red cable → Positive (+) pad
• Black cable → Negative (–) pad

3. Board Insertion

• Orient the USB-C slot uppermost in the barrel moulding.
• Carefully slide the VREG2 board into the barrel using the guide slots.
• Press until the USB-C connector is flush with the front of the barrel.

4. Internal Locking Segment

• Before fitting the locking segment, bend the cable through the slot on the left side below the rear of the VREG board.
• Lightly clean the bonding faces of the segment and housing with isopropyl alcohol or acetone and when dry, apply a small amount superglue to one of the bonding faces to secure it.
• Apply a small  quantity of non-silicone sealant to the cable entry hole to reduce moisture ingress.

⚠️ Do not use silicone sealants as they permanently damage the membrane.

5. Cable Termination

• Fit the correct cable crimps to the conductors after ensuring they are compatible with the membrane type.
• If needed, order a M-5PKT fixing kit contains two cables to the M-Series and two for the MDL Series membranes.

6. Panel Installation

• Drill or prepare a 36 mm hole in the panel using a cutter or step drill.
• Insert the barrel housing into the hole.
• Hand-tighten the external locking ring to secure the assembly.