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Transparent plastic cover on aluminium base enclosure, 5.38 by 3.75 by 3.06 inches

Robertshaw

Robertshaw 366D8 Malfunction Detector DPDT 5A 120VAC 0-300 Hz 4.5 G 3.5 G NEMA 4X -40 to 203 F

SKU CH-99DW-EXCQR

A malfunction detector that senses vibration from 0 to 300 Hz and trips a DPDT contact at up to 5 A, 120 VAC

  • TypeMalfunction Detector
  • ColorTransparent
  • DPDT contacts switch two circuits independently
  • 5 A at 120 VAC handles motor-start loads
  • 0–300 Hz range covers low- and high-frequency vibration
  • NEMA 4X enclosure resists wash-down and corrosion
  • Operates from -40 °F to 203 °F in harsh environments

Purpose and User

The Robertshaw 366D8 is a malfunction detector built for machinery protection. It suits maintenance engineers and plant operators who need reliable vibration monitoring on motors, pumps or fans in harsh environments.

Contact and Electrical Rating

The switch uses a DPDT contact rated at 5 A and 120 VAC across a 0 to 300 Hz frequency range. This electrical specification determines whether the device can safely interrupt your control circuit.

Enclosure and Mounting Context

A NEMA 4X plastic cover with aluminium base withstands -40 to 203 F and measures 5.38 in by 3.75 in by 3.06 in. Remote electrical or manual reset options simplify integration, while the horizontal 4.5 G and vertical 3.5 G ranges cover typical industrial vibration profiles. Builders needing different G thresholds or a non-NEMA 4X enclosure should look elsewhere.

Highlights

  • DPDT contacts switch two circuits independently
  • 5 A at 120 VAC handles motor-start loads
  • 0–300 Hz range covers low- and high-frequency vibration
  • NEMA 4X enclosure resists wash-down and corrosion
  • Operates from -40 °F to 203 °F in harsh environments

Specifications

BrandRobertshaw
Model366D8
TypeMalfunction Detector
ColorTransparent

Questions about this item

What does the 4.5 G horizontal and 3.5 G vertical range mean when the detector is installed on equipment?

Those figures set the vibration acceleration thresholds. If horizontal motion exceeds 4.5 G or vertical motion exceeds 3.5 G, the DPDT contacts trip to signal a malfunction.

How does the 0 to 300 Hz frequency range limit what the switch can detect?

The switch only responds to vibration within that band. Frequencies below 0 Hz or above 300 Hz will not actuate the contacts, so very low or very high speed imbalance may go unnoticed.

What mounting clearance is needed for the 5.38 in length, 3.75 in width and 3.06 in height enclosure?

Allow at least those external dimensions plus wiring space. The plastic cover with aluminium base fits a standard NEMA 4X cut-out, and the remote electrical or manual reset requires front access.

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