The STEGO MFR 012 Mechanical Hygrostat (Part No. 01220.0-00) is a high-precision enclosure humidity controller designed to monitor and regulate relative humidity inside industrial electrical cabinets, PLC enclosures, telecom outdoor equipment, and automation panels. Condensation occurs when relative humidity spikes alongside temperature shifts, risking corrosion, short circuits, and premature electronic failure.

Operating without an external electrical power supply, the MFR 012 utilizes a humidity-sensitive synthetic fiber element to actuate its contact mechanism reliably. It features a wide adjustable setting range from 35% to 95% RH. Equipped with a change-over SPDT (Form C) contact, the Stego 01220.0-00 can simultaneously switch on an enclosure heater to raise temperature and drop relative humidity, or trigger a cooling fan/alarm system when humidity surpasses critical limits. Housed in flame-retardant plastic according to UL94 V-0 and easily mounted on 35mm DIN rails, it delivers reliable long-term climate protection.

• Manufacturer: STEGO (Germany)
• Product Series: MFR 012 Series (Mechanical Hygrostat)
• Part Number: 01220.0-00
• Setting Range: 35% to 95% RH (Relative Humidity)
• Switching Difference (Hysteresis): Approx. 4% RH (at 50% RH)
• Contact Type: SPDT Change-over contact (Form C)
• Service Life: > 50,000 cycles
• Maximum Switching Capacity:
  - Resistive Load: 5A @ 250VAC / 5A @ 120VAC / 20W @ 24VDC
  - Inductive Load (cos φ = 0.6): 0.2A @ 250VAC
• Sensing Element: Synthetic fiber hair element
• Electrical Connection: 3-pole terminal, clamping torque 0.5Nm max., lead wire 2.5 mm² max.
• Mounting: Clip for 35mm DIN rail (EN 60715)
• Casing Material: Plastic according to UL94 V-0, light grey
• Protection Degree: IP20
• Dimensions: 67 x 50 x 38 mm
• Weight: Approx. 60g
• Operating / Storage Temperature: 0°C to +60°C (+32°F to +140°F) / -20°C to +80°C (-4°F to +176°F)
• Approvals & Certifications: VDE, UL Recognized, EAC, RoHS compliant