Elevator control systems are complicated and sensitive circuitry since, most control modules used nowadays are microprocessor based.  Therefore, delicate to transient voltages and currents or to power quality(Harmonics, swells, transient surges, phase failure, overvoltage and undervoltage, and  lightning events) . The cost associated for replacing circuit boards and drives is always expensive and these events are totally unpredictable.

Below figure depicts the abnormality of a typical power supply of an equipment.

Fig.1 Ideal sinusoidal AC power supply (Left); Polluted quality of a power supply detrimental to load or equipment (Right)

SERVICE PROVIDERS TERMS FOR DESTRUCTIVE POWER EVENTS

Most Elevator OEM provider on their service contracts on customers whether it be comprehensive or non-comprehensive, does not and will not cover warranty of parts and performance when catastrophic events like lightning, surge caused by local utility provider or internal to the building power disturbances transpires. The cost incurred due to these events will always be shouldered by building owner or management. Even to defect not associated with power quality most of the times is blamed by service technicians on this issue.

COST INCURRED IN POWER DISTURBANCES

Major surges, transient voltages and lightning strikes can destroy and actively deteriorate sensitive electronic circuit elements of

• Motion Controller & communication modules
• Power Supply circuits
• Drives/Inverters
• Sensors
• LCD Displays

Controller modules cost about P60K to P150K pesos while, P200K to P500K for drives depending on its corresponding capacity. These elevator parts are not cheap so it is best recommended that equipment should be protected to avoid any circumstantial cost due to part defect, interruption of operation and legal liability or lawsuit when an accident happens.

MITIGATION AND SOLUTION TO POWER QUALITY AND MAJOR CATASTHROPIC EVENTS

Most elevator company will insist that their units are substantially protected from these events. But, it is always wise and economical to isolate and protect elevator with Automatic Voltage Regulators (AVR) and Surge Protective Device (SPD) since AVR and SPD are way cheaper than the expensive OEM parts.

A superb design and reliability tested AVR can eliminate these voltage dips, swells, over-voltage and under-voltage events.  However, it can not filter transient and surge voltages which last about less than a millisecond.  Commercial available AVR has a typical response time of 0.1 of a second. This is where a Surge Protective Device (SPD) or Transient Voltage Surge Suppressors (TVSS) is necessary to cut-off surge and transient voltages from reaching the protected load, as in the case-the elevator.

Fig.2 Typical surge or transient voltage event which only last about 3/60th of a second

Since, the market is flooded with cheap and unreliable AVR, TVSS and SPD’s. In which, in some cases even cause defects to elevators. FRB Elektromek guarantees to specify only the appropriate size, best and cost-efficient brands of AVR and SPD already tested in elevator application for years.

Should you have requirements on protecting your lift equipment, FRB Elektromek has a solution for that. You may contact us for free consultation and sizing of AVR and SPDs.