APC Line-interactive UPS

What is APC line-interactive UPS?

Line-interactive UPS keeps the load on utility power most of the time and uses an autotransformer with Automatic Voltage Regulation (AVR) to correct sustained low or high voltage without engaging the battery. On a true outage, transfer to battery takes 2 to 6 ms typical depending on the model (APC's data sheets), fast enough for most modern server, networking and storage power supplies. It suits most SMB server, networking and POS loads.

APC's line-interactive catalog covers four families: Back-UPS Pro (BR / BX) for workstation and small-office protection, Smart-UPS C (SMC) for entry-tier server, Smart-UPS (SMT) for the workhorse rack tier, and Smart-UPS X (SMX) for extended runtime and convertible chassis. UPSPLUSBATTERY.CA offers the line with matching APCRBC replacement batteries. For loads that can't tolerate transfer time, see APC double-conversion online UPS. For the standby / entry tier below this, see APC standby UPS. Full APC catalog: APC UPS.

APC line-interactive families

SMT covers most rack deployments. SMX adds external battery support when stock runtime is insufficient. SMC SmartConnect-equipped models (SMC1500-2UC) include cloud-based UPS monitoring without the AP9641 card. Back-UPS Pro covers the workstation tier where pure-sine and PowerChute integration aren't required.

How to choose

Sizing: VA and watts

Smaller SMT and SMC models run roughly 0.6 to 0.7 power factor: the SMT1500 is rated 1440 VA / 1000 W and the SMC1500 1440 VA / 900 W. SMX models step up to ~0.9 PF on most SKUs, SMX2200 delivers 2200 VA / 1980 W. Modern dense IT loads draw close to unity PF, so the watt rating is the binding number. Add nameplate watts of all loads, multiply by 1.25 buffer, pick the UPS whose watt rating exceeds. UPS sizing guide.

Smart-UPS C vs Smart-UPS

SMC = entry-tier business UPS; SMT = full-featured business workhorse. SMC is pure sine but does not accept the AP9641 SmartSlot network management card and lacks the deeper PowerChute integration of SMT. For one or two servers in a small office, SMC is sufficient. For a managed rack with VMware / Hyper-V shutdown automation and SNMP monitoring, choose SMT or SMX.

SMT vs SMX

Same VA range, same line-interactive topology, same pure sine output. SMX adds support for external battery packs (XLBP series) for extended runtime, comes in a rack/tower convertible chassis, and ships with the SmartSlot bay populated on the -NC variants. If runtime requirements exceed the stock, choose SMX.

Spec reference

Smart-UPS and Smart-UPS X work with APC's PowerChute software. Most SMT and SMX have an open SmartSlot bay accepting the AP9641 Network Management Card; -NC variants ship with the card already installed.

Replacement batteries

APCRBC stands for APC Replacement Battery Cartridge, the part-numbering system APC uses for every factory-approved cartridge. The cartridge number is on the unit label and listed in the user manual. We stock compatible replacement batteries matched on voltage, capacity, terminals and connectors. 1-year UPSPLUSBATTERY warranty on aftermarket. See APC Smart-UPS replacement batteries and APC Back-UPS replacement batteries.

Installation and warranty

Up to 1500 VA: NEMA 5-15P plug-and-play. 2200 / 3000 VA: typically L5-30P or NEMA 5-20P depending on model. 230 V variants (-I / -HV suffix): IEC C20 inlet. Warranty (APC data sheets): 36 months on the UPS and 24 on the battery for Smart-UPS SMT and SMX; 24 months on Smart-UPS C (SMC); 36 months on the UPS and 12 on the battery for Back-UPS Pro. Coordinated through our Canadian team. Shipped from Canada: see shipping policy for rates and timing.

FAQ

Why is line-interactive enough for a server room?

A 2 to 6 ms typical transfer (APC's data sheets, depending on the model) is fast enough for most modern servers, switches and storage devices. AVR corrects routine brownouts and surges without going to battery, extending battery life. Online double-conversion is only required for medical, VoIP PBX, precision lab, or anywhere zero-transfer is mandatory.

Pure sine wave on battery?

Yes on Smart-UPS C, Smart-UPS, and Smart-UPS X. Back-UPS Pro G models (for example BR1500G) produce simulated sine on battery (acceptable for desktop and consumer electronics, marginal for active-PFC server PSUs); MS models (BR1000MS, BR1500MS) produce sine wave. For any server load, choose SMC, SMT, or SMX.

Can I add network monitoring?

Yes on SMT and SMX: open SmartSlot bay accepts the AP9641 Network Management Card for SNMP, web, Modbus, and integration with VMware, Hyper-V, Linux, Windows shutdown agents. -NC variants ship with the card pre-installed. SMC1500-2UC includes SmartConnect cloud-based monitoring without an add-on card.

How long does the battery last?

APC gives 3 to 5 years (4 to 6 on some models) in a climate-controlled room. Above 25 °C ambient, every 8 °C roughly halves life. PowerChute and the front-panel LCD show a replace-battery alert. When to replace UPS battery.

Hot-swap batteries?

Yes on current Smart-UPS C, Smart-UPS and Smart-UPS X models: the APCRBC cartridge slides out the front while the UPS continues to protect the load. On Back-UPS Pro, check the user manual. Reset the install date via the front panel afterward.

Add external battery packs?

Smart-UPS X (SMX) supports XLBP external battery packs for extended runtime. APC lists SMX120BP and SMX120RMBP2U packs for SMX models; check APC's data sheet for the pack that matches your model. SMT models do not support external batteries; if extended runtime is needed in the SMT VA range, step up to SMX.

Canadian warranty?

Yes: APC Smart-UPS, Smart-UPS X, Smart-UPS C, and Back-UPS Pro factory warranty terms explicitly cover USA and Canada. RMA coordinated through our Canadian team. Shipped from Canada.