Description
The Honeywell 51303940-150 is a UCN (Universal Control Network) Dual Fan Assembly with integrated alarm functionality, manufactured by Honeywell for use in DCS control cabinets . This cabinet cooling unit combines two industrial fans with a temperature monitoring circuit and a passive dry-contact alarm output, ensuring continuous thermal management for critical control electronics .
The Honeywell 51303940-150 serves as a field-replaceable cooling module for Honeywell UCN series cabinets, where it prevents overheating of DCS cards, power supplies, and communication processors. Its redundant dual-fan design and alarm capability make it an essential maintenance spare for facilities operating legacy Honeywell control systems .
Application Scenarios
A petrochemical plant in the Middle East operates a Honeywell TDC 3000 DCS with UCN cabinets distributed across multiple process units. During summer months, ambient temperatures in the control room occasionally exceeded 45°C, pushing cabinet internal temperatures toward the upper limits of the installed electronics. The plant’s maintenance team discovered that the original single-fan cooling units had become unreliable—when a fan bearing seized, the cabinet temperature would rise unchecked until operators noticed unexplained card faults.
The solution was replacing the aging cooling units with Honeywell 51303940-150 Dual Fan Assemblies. The redundant dual-fan design provided immediate benefit: if one fan slowed or stopped, the second fan maintained airflow, preventing sudden overheating while the alarm signal alerted the control room . The integrated temperature sensor and passive dry-contact output connected directly to the DCS, where operators received an early warning before cabinet temperatures reached critical levels.
After installation, the plant experienced one fan failure during peak summer operations. The Honeywell 51303940-150 continued cooling with the remaining fan, and the alarm triggered a maintenance work order. The replacement was completed during the next scheduled shift without process interruption. The plant’s instrumentation supervisor noted that the Honeywell 51303940-150’s integrated assembly simplified field replacement—no separate fan, bracket, or wiring components were needed .
Parameter
| Parameter | Value/Description |
|---|---|
| Product Model | Honeywell 51303940-150 (MC-FAN611) |
| Manufacturer | Honeywell |
| Product Category | UCN Dual Fan Assembly with Alarm |
| System Compatibility | Honeywell UCN DCS Cabinets / TDC 3000 |
| Input Voltage | 85–132 V AC, 47–63 Hz |
| Rated Current | 0.25–0.5 A |
| Fan Configuration | Dual fans, 3 blades each |
| Rated Speed | 3100 RPM (per fan) |
| Fan Size | 120 × 120 mm industrial cooling fans |
| Alarm Type | Passive dry contact (fan failure / over-temperature) |
| Contact Rating | 0.5 A |
| Weight | Approx. 1.88–3.22 kg |
| Dimensions | Approx. 390 × 141 × 55 mm |
| Mounting | Standard UCN cabinet mounting (horizontal) |
