Lesson Learned Statement:Euroclean Model UZ948 HEPA vacuum cleaners draw current above that for which the cords and plugs are rated.
Discussion:A Euroclean Model UZ948 HEPA Vacuum used by BHI at U-Plant and at other Hanford facilities tripped the circuit breaker supplying its outlet. Evaluation by the chairman of the Hanford Electrical Codes Board determined that the vacuum nameplate rating was more than the rated capacity of the cord and plug. Receptacle circuits compatible with the installed attachment plug are not adequate for the vacuum load. These conditions can lead to overheating of the attachment plug, flexible cord, receptacle, or circuit wiring and do not comply with the National Electrical Code (NEC).
This notice applies specifically to Euroclean Model UZ948, however other models may have similar problems.
Analysis:The Model UZ-948 vacuum has three motors that provide a maximum flow rate of 270 CFM. When the unit is started, one switch turns on the first two motors and a second switch turns on the last motor. The high amperage draw when the unit is started may trip circuit breakers. During a simulated field test of a unit at the ALARA Center, the following line currents were recorded using a digital ammeter:
Motors 1 and 2 running under load (moving air only) - 11.8 Amperes
Motors 1 and 2 running under no load (suction hose blocked) - 10.5 Amperes
Motors 1, 2, and 3 running under load (moving air only) - 14.6 Amperes
Motors 1, 2, and 3 running under no load (suction hose blocked) 11.8 Amperes
Because the normal load on this unit is the work involved in moving air, blocking the suction hose will reflect the no load condition. As expected, the line currents dropped when the air movement stopped. However, the actual loaded condition in the field will include moving air along with other material containing additional mass. The combination of air and additional mass will require more work, and thus will present an additional load on the unit. The nameplate on the unit lists 14 Amperes full load for 2 motors and 19.4 Amperes full load for 3 motors.
Other problems identified with the equipment include:
Recommended Actions:Facilities with Euroclean Model UZ948 HEPA vacuum cleaners should replace or repair the affected units according to the options below:
* Return/retire existing units and replace with new equipment listed with a nationally recognized testing laboratory such as Underwriters Laboratory (UL).
* Replace the 14/3 gage power cord with 12/3 gage cord and replace the attachment plug with a 5-30P.
* Replace the attachment plug with a 5-20P and physically disconnect motor No. 3.
Originator:Fluor Hanford, Inc.
Contact:Project Hanford Lessons Learned Coordinator; (509) 373-7664;
Name Of Authorized Derivative Classifier:Not required
Name Of Reviewing Official:John Bickford
Priority Descriptor:Yellow / Caution
Keywords:HEPA vacuum; Euroclean; circuit breaker; electrical overload
References:HWESB Minutes for 7/11/2001
Electrical Safety Bulletin ESB-2001-03
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DOE Function / Work Categories:Business and Support Services
Decontamination & Decommissioning
ISM Category:Analyze Hazards
Hazard:Electrical / NEC
Fire / Smoke / NFPA
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