IS DistributionsEnquireHow to size a UPS for CCTV, network and server equipment
Sizing an uninterruptible power supply means matching its rating to the load it protects and the time it must keep that load running. This guide explains VA and watts, how to add up a load of recorders, switches and servers, how to read runtime charts, and when to choose line-interactive or double-conversion models.
What this guide covers
- VA versus watts and the power factor of a UPS
- Adding up the load: recorders, PoE switches, servers, PCs and monitors
- Runtime at different loads and extended battery packs
- Line-interactive versus double-conversion (On-Line) topologies
- Rack versus tower, and network management cards for automatic shutdown
- Battery life and replacement planning
Typical applications
- Guard-house CCTV racks
- Office server rooms
- Clinics and shops with payment terminals
- Industrial control panels
What you will find
- Step-by-step sizing method with headroom
- How a PoE switch's camera load appears on the UPS
- Choosing between a few minutes for graceful shutdown and long runtime for continued operation
- Where the APC and Hikvision ranges on this site fit
Functions vary by model and firmware; see each model page and the official datasheet.
Selection questions
- What is the total load in watts, measured or from datasheets?
- How many minutes must the equipment keep running after a power cut?
- Should servers or recorders shut down automatically before the battery is empty?
- Is the mains supply unstable, with frequent voltage dips?
Prepare an enquiry
ISD in Kuching, Sarawak handles UPS sizing enquiries for projects in Sarawak and Malaysia. Send the full model code and quantity, or describe the site. Supply only; ISD confirms the model separately.
Describe your requirementFrequently asked questions
What is the difference between VA and watts?
VA is apparent power; watts is real power. A UPS has a rating in both, and the load must stay below each. Most IT loads have a power factor close to one, so the watt rating is usually the limit.
How much runtime do I need?
Enough for the longest typical outage, or at least enough for a graceful shutdown. Runtime drops as load rises; the official runtime chart for each model gives the figures.
Which UPS ranges does ISD list?
APC Back-UPS, Smart-UPS, Smart-UPS On-Line and Easy UPS, plus Hikvision UPS models within the premises distribution range; see the linked guides.
How to size a UPS for CCTV, network and server equipment - models on this site
- BR1200SIAPC
- BR1300MIAPC
- BR1500GIAPC
- BR1600MIAPC
- BR1600SIAPC
- BR24BPGAPC
- BR650MIAPC
- BR900MIAPC
- BX1200MI-MSAPC
- BX1600MI-MSAPC
- BX2200MI-MSAPC
- BX625CI-MSAPC
- BX750MI-MSAPC
- BX950MI-MSAPC
- SMC1000I-2UCAPC
- SMC1000ICAPC
- SMC1500I-2UCAPC
- SMC1500ICAPC
- SMC2000IAPC
- SMC2000I-2UAPC
- SMC3000IAPC
- SMC3000RMI2UAPC
- SMT1000CAPC
- SMT1000ICAPC
- SMT1000RM2UCAPC
- SMT1000RMI2UCAPC
- SMT1500CAPC
- SMT1500ICAPC
- SMT1500RM2UCAPC
- SMT1500RMI2UCAPC
- SMT2200CAPC
- SMT2200ICAPC
- SMT2200RMI2UCAPC
- SMT3000CAPC
- SMT3000ICAPC
- SMT3000RM2UCAPC
- SMT3000RMI2UCAPC
- SMT750CAPC
- SMT750ICAPC
- SMT750RM2UCAPC
103 more related models are listed in the product catalogue.
Related guides and categories
- APC UPS series guideGuide
- APC replacement battery cartridges (RBC) guideGuide
- Hikvision Premises Distribution System (cabling, UPS and monitors)Hikvision guide
- UPS & backup powerCategory
- Power, UPS & solarCategory
- All series & technology guidesGuide
Reference
Written by ISD from manufacturers' public product information; confirm specifications on each model page and the official datasheet. Checked 2026-11-01.