Abstract of RIIS Report ( SH-1960-3 )

National Institute of Occupational Safety and Health, Japan

Research on Finding-Out of Earth-Fault Points in Low Voltage Circuits

SH-1960-3-1

S.KOZUKI and R.TANAKA

: Earth-fault detectors have been so far widely used in factories in order to detect earth-faults in low voltage circuits, but even if detected by them, as it becomes necessary to find out earth-fault points by stopping electric supply service, they are not of fully practical use.
The writers studied on how to find out earth fault points under power supply and as a result of some experiments which were done at large factories, such as of iron and steel, chemical and spinning industries, we showed that our method was very useful for preventing accidents due to earth-faults.

On Hazards of Igniting Gun-Powder Through Breakage of Incandeacent Lamps or Fluorescent Lamps (2nd Report)

SH-1960-3-2

S.KOZUKI and K.SAKANUSHI

: We indicated, on the first report, the results or hazards of whether a bit of gun-powder scattered on the surface of incandescent or fluorescent lamp would be ignited through breakage of the lamps or not.
    This time we studied on hazards of igniting of a bit of gun-powder through breakage of 40 watts rapid start and 20 watts glow-start fluorescent lamps, and obtained the following results.
  1. In cases of 40 wat's rapid start fluorescent lamps,
   (a) T.N.T. black carlit and ammonium nitrate explosives are not ignited,
   (b) Black-powders are occasionally ignited by waste heat of filament, but seldom on discharge.
  2. In cases of 20 watts glow start fluorescent lamps,
   (a) T.N.T and Black carlit are not ignited,
   (b) Black-powders ignited by waste heat of filament, but seldom on discharge.
    By the results of the first and second reports, we found out that when a working incandescent lamp or a fluorescent lamp is broken, the former is far more hazardous concering the ignition of gun-powder.

Research of Ventilation in Plant (3rd Report)

SH-1960-3-3

T.KONDO

: Experimentally, we measured the velocity and the temperature of the convection flow over heated sources, in order to improve the design of exhaust system for hot gases and fumes from the furnace and the open tank etc. Instead of the using convection loss, to calculate the volume of convection air, we proposed the using air temperature, which can be measured more easily in plant. Besides, the deflection of convection flow by the traverse wind was conjectured from our study.

JNIOSH

Abstract of RIIS Report ( SH-1960-3 )

National Institute of Occupational Safety and Health, Japan

Research on Finding-Out of Earth-Fault Points in Low Voltage Circuits

On Hazards of Igniting Gun-Powder Through Breakage of Incandeacent Lamps or Fluorescent Lamps (2nd Report)

Research of Ventilation in Plant (3rd Report)

Other Publications