# Power Quality Impact and Its Assessment: A Review and a Survey of Lithuanian Industrial Companies
## 4 Results
The particular sensitive part is at the end--ultraviolet coating and varnish curing. Both of these processes must be continuing. Next, voltage sags are dangerous to boiler stations. The input of biomass is inert, the forced smoke release cannot work without power supply. Moreover, the combustion continues, which poses a risk of explosion. Next, PQ impact on the grinding equipment is also dangerous because their shafts have high inertial forces. Braking is performed mechanically and electrodynamically--such facilities cannot work without power supply.\"
* \"The technological process is interrupted after each voltage sag, the production lines are interrupted, the restart takes up to 2 h. Particularly sensitive equipment is 0.4 kV induction motors installed in the automated lines. In the future, the company plans to install PQ monitoring equipment.\"
* \"Voltage sags interrupt the technological processes. Despite the fact that the appropriate protections are triggered, it does not always help, the equipment stops, and the restart is required. This generates outages, economic losses are incurred, equipment failures are caused, the quality of product suffers, production terms are prolonged.\"* \"The technological process is interrupted after each voltage sag, the production lines are halted, the restart takes up to 2 h.\"
* \"Our company rarely experience heavy losses due to voltage sags (e.g., repair of pumps and equipment). Usually, voltage sags disrupt the process of water supply, which leads to complaints from our customers.\"
* \"The technological process is interrupted after each voltage sag. The equipment can be damaged. The hot water boiler stops. The restart of the equipment takes up to 2 h, sometimes longer. Moreover, the work of the network pumps is affected, and pressure fluctuations are caused. As a result, hydraulic shocks occur and the pipelines are damaged. The danger to occupational safety and health increases.\"
* \"When the residual voltage is equal to 0 V, the pumps and all other equipment stop. The temperature drops, the service is unavailable, the temperature schedule is not followed, direct and indirect losses are incurred, and the equipment is damaged. The likelihood of hydraulic shock increases.\"
* \"Particularly sensitive equipment are 0.4 kV induction motors installed in the automated lines. In the future, the company plans to install PQ monitoring equipment\". * \"We manufacture semiconductor devices. The manufacturing process is long and continuous, therefore, if any part of the chain is interrupted by voltage sag, economic losses are incurred.\"
* \"Voltage sags negatively affect the production of plastic and metal containers (package). When the protective relays are triggered, the plastic melting machines, metal press machines, and welding equipment stop.\"
* \"Voltage sags interrupt the technological process--the gas and biofuel boilers together with the electric generator stop. If the equipment is not damaged, the restoration of heat and electricity production takes 1-2 h, sometimes is longer, depending on the voltage sag depth and duration. The company suffers economic losses by not generating and not supplying both heat and electricity.\"
* \"The knitting and heating processes are damaged after each voltage sag. A net damaged at the knitting stage becomes waste--it cannot be sold or used for other purposes. Each time the minimum loss is EUR 600-3000 per machine (we have eight machines) plus lost time. Let us continue with the heating process--the rope stops and as a result is overheated, the impregnant is squeezed out, and the rope becomes defective. Losses--EUR 3 per meter (the length of the rope is 2000 m). In the future, the company plans to install PQ monitoring and mitigation technologies.\"
* \"We are a food industry company and we use modern food production equipment to produce our products. Most of the process is fully automated and is automatically stopped by the protection when voltage sag depth exceeds 10%.