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Repetitive tasks carried out by packaging workers of fertilizer producer company. These task led to some complains of pain and fatigue on upper body part of the workers based on Nordic Body Maps (NBM) questionnaire. This is because the workers work continuously for eight hours per shift and no recovery period. This study aims to determine risk level of musculoskeletal disorders and break time calculation. In this study, using Occupational Repetitive Actions (OCRA) index to reduce the risk level. The samples according to expert judgement criteria are three workers (packer clamper, packer tailor and loader). The improvement in this study is designing work methods with break time calculation. This improvement shows the risk reduction on the left hand of the packer clamper from 4,2 to 3,4 and the right hand from 9,9 to 8,2. Risk reduction on the left hand of the packer tailor from 3,44 to 2,2 and the right hand from 5,7 to 2,26 while the risk level on the left hand of loader from 1,4 to 0,87 and in the right hand from 2,17 to 1,18.

No abstract

In the animal feed industry, hammer mill machinery plays an important role in the smashing of raw materials. By 2017, in an animal feed industry there has been a fire on the dust collector that almost burned down the hammer mill machine. In previous years also often occur sparks arising due to the knife rubbing against the metal that carried away with raw material. However, the fire will not increase if the hammer mill machine operators are competent in extinguishing the fire. The purpose of this study is to find out how much the effects of hammer mill machine fire fighting in terms of safety scenarios that exist either from human procedures or automatic safety procedures performed by existing safety devices. In this study, using a combination of calculations between Human Error Probability (HEP) values obtained from Human Reliability Assessment (HRA) calculations using SPAR-H method and reliability calculation of hammer mill machine components obtained from downtime data for four years, 2014 until 2017. The total probability of outcome fire controlled increases from 0.177940 to 0,6393 and the total probability of outcome fire uncontrolled decreases from 0,82206 to 0,36068.

Around 66% of power plants in Indonesia are still sourced from coal and oil. On the other hand, Indonesia is rich in renewable energy potential but still has minimal utilization. Furthermore, the voltage at power plants that are small and less stable is also often a nuisance. Thus, an innovative hybrid, solar and hydroelectric power plant with a PID (Proportional Integral Derivative) based voltage stabilizer was created. PID-based voltage stabilizer control is generated in the form of PWM (Pulse Width Modulation). The results obtained in this study are PID control can produce the lowest voltage of 12.78 V and the highest voltage of 13.96 V with a setpoint of 13.4 V. The power generated from solar, hydro, and hybrid power plants is 11.8 Watts, 9.4 Watts, and 14.85 Watts. As for Charging the Battery, an increase of 2.72 V was obtained in 24 hours. As for the storage side, the Battery can supply a 15 watt incandescent lamp for 8 hours 55 minutes while leaving 20% of the total capacity.