Articles - Battery Backup Power UPS Systems

Elevator Battery Backup UPS Systems November 16 2017, 0 Comments

Elevator UPS Battery Backup

As building code enforcement becomes more aggressive, the need to provide at least 90 minutes of backup power to elevators in multi-story buildings has become essential to passing final inspection. 

Typically, a standby generator has been used to fulfill this requirement, but due to maintenance requirements and new air quality control regulations, the use of UPS (uninterrutible power supply) battery backup systems has been on the rise. 

There are a few extremely important factors that need to be considered when using a UPS/battery backup system as the backup power source for an elevator. These factors are listed below. 

1. There can be no back feed electricity from the elevator. The major elevator manufacturers like to add their “energy saving” regenerative systems to their new elevator installations. This type of regenerative system can not be used with a UPS because it back feeds power to the UPS rather than to the main electrical panel, which causes damage the UPS. 

Elevator Regenerative Power Specification Example

2. The fire inspector will want to see a worksheet stamped by a local or state licensed electrical engineer that shows that the UPS/battery backup system will support the elevator, its accessories, and exhaust fans for at least 90 minutes under maximum load conditions. Battery Backup Power, Inc. can provide battery backup time calculations once we have the electrical specifications, but a local electrical engineer will need to verify and stamp them to satisfy permitting requirements. 

Example Battery Backup Time Calculation For Elevator

3. As per code, there must be some sort of notification that the elevator is on backup power when utility power is lost. For example, a light that illuminates in the elevator car when the elevator is operating on battery power alone. Battery Backup Power, Inc. includes a dry contact board on the UPS/battery backup system to send the signal. A circuit from the dry contact board to the elevator must be provided/installed by an electrician or the elevator company. 

BBP-3P Dry Contact Board

4. The UPS/battery backup system load capacity needs to be sized to not only handle the normal operating current, but the inrush/peak current of the elevator and any attached device (fans, etc). The UPS/battery backup system must be sized above the peak/inrush current sufficiently to allow proper heat dissipation with continuous use.

Example 3 Phase UPS Battery Backup For Elevator

5. Some cities require that any battery backup system with 50 or more gallons of electrolyte must be contained in a separate fire rated room. Most UPS/battery backup systems that can support elevators for at least 90 minutes will be at or exceed this threshold. 

Battery Electrolyte Example Specification

6. Every UPS/battery backup system for made for use with an elevator is typically custom built to that specific elevator load requirement. Due to this fact, the UPS/battery backup system will not have a UL certification sticker. Instead, the system will be built to ANSI/UL certification standards using UL breakers and will need a field testing company such as TUV or Intertek to complete a "field certification" of the main UPS/battery backup and associated external battery cabinets to satisfy building permit requirements. After the "field certification inspection", TUV or Intertek will affix a sticker to the system that shows the city inspector that the system complies with ANSI/UL safety standards. This "field inspection" typically runs between $4k and $6k depending on the location and the field certification entity used. 

Field Inspection Certification Example

7. Installation is straight forward and simple for a licensed electrician. Most systems are 208 Volts, 3 Phase, WYE configuration, 5 wires (3 hots, 1 neutral, 1 ground) input and output. There are five wires going in from the utility company or main electrical panel and five wires going out to the elevator. Operation after turning the system on is completely automatic. 

Elevator UPS Battery Backup Terminal Block Wiring

For assistance with providing an elevator with battery backup power, contact us at (855) 330-7799 or engineering@batterybackuppower.com

To browse a selection of UPS / Battery Backup systems that are typically used with elevators or in commercial/industrial applications, please visit our 3 Phase Battery Backup Power UPS collections page.