APC Double Conversion Online UPS

What is APC double-conversion online UPS?

Online (double-conversion) UPS runs the load permanently from the inverter, utility AC continuously rectified to DC, then re-inverted to clean AC before reaching equipment. Transfer time is effectively zero during a power event and the output sine wave is fully regenerated at all times. It is the usual topology for medical equipment, VoIP PBX, precision laboratory gear, industrial control, and edge data centres where line-interactive transfer is unacceptable.

APC's online catalog spans single-phase Smart-UPS SRT (SLA) and Smart-UPS Ultra (SRTL lithium-ion) for IT closet and edge compute, Easy UPS On-Line SRV, scalable Symmetra LX (4 to 16 kVA) and Symmetra RM, three-phase Symmetra PX (10 kW to 500 kW), and Galaxy V series three-phase for data-centre and industrial. UPSPLUSBATTERY.CA offers the single-phase range with matching APC Smart-UPS RT replacement batteries. Line-interactive equivalents at APC line-interactive UPS. Full APC catalog at APC UPS.

APC online families

For SMB and mid-enterprise online needs the shortlist is the SRT from 1 to 10 kVA or the SRTL Smart-UPS Ultra. SRT 5 to 10 kVA covers the dense-rack tier on 208/230 V. SRTL adds lithium-ion battery life and compact 1U to 4U chassis for retail back-of-house and edge.

How to choose

When online is required

When the load can't tolerate the transfer of a line-interactive UPS (APC gives 4 to 6 ms typical on the Smart-UPS SMT): medical diagnostic, VoIP PBX, precision lab, industrial control, active-PFC supplies sensitive to frequency deviation. When utility waveform is unusually dirty (high THD, frequent frequency drift). For typical server room and network closet, line-interactive is usually sufficient and costs less. Line-interactive vs online UPS.

SLA SRT vs Lithium SRTL

SRT uses sealed lead-acid batteries; APC gives 3 to 5 years. SRTL Smart-UPS Ultra uses lithium-ion batteries; APC gives 5 to 10 years and a 60-month warranty. For long deployments, hot ambient or hard-to-reach racks, the SRTL means fewer battery replacements. Smart-UPS vs Smart-UPS RT.

Single-phase vs three-phase

Up to 10 kVA single-phase covers most rack-level deployments. Above that, Symmetra LX / RM single-phase scales to 16 kVA, and Symmetra PX modular three-phase scales from 10 kW to 500 kW for data-centre rows. Galaxy series covers heavy three-phase 10 kVA to 1.5 MW for facility and industrial.

Sizing

SRT 1 to 3 kVA: typically 0.9 PF (SRT3000RMXLI delivers 3000 VA / 2700 W). SRT 6 to 10 kVA: unity PF (SRT6KXLT delivers 6 kVA / 6 kW). SRTL: unity PF or close to it (SRTL5KRM2UT 4900 VA / 4900 W, SRTL3KRM1UC 2880 VA / 2850 W). Add nameplate watts of all loads, multiply by 1.25 buffer, pick the UPS whose watt rating exceeds. Sizing guide.

Spec reference

Replacement batteries

SRT line uses APCRBC140 (5 to 10 kVA, 192 V), APCRBC141 (SRT2200), APCRBC152 (SRT3000), APCRBC155 (SRT1500). SRTL uses APC lithium-ion batteries from APC only (APCRBC173-LI on the SRTL 2.2 and 3 kVA per APC's data sheets; SRTL180RM2UBP as listed for your model). We stock compatible SLA replacement cartridges matched on voltage, capacity, terminals and connectors. 1-year UPSPLUSBATTERY warranty on aftermarket. See APC Smart-UPS RT replacement batteries.

Installation and warranty

SRT 1500 / 2200 / 3000 plug-and-play (NEMA 5-15P, L5-30P, or IEC C20 depending on the model). SRT 5 kVA on L6-30P; 6 / 8 / 10 kVA hard-wired by licensed electrician per CSA. SRTL 5 kVA accepts plug-in or hard-wire. Symmetra LX / RM tower deployment plug-in up to ~6 kVA, hard-wired above. Symmetra PX and Galaxy require commissioning by Schneider Electric service; a site survey is recommended before ordering. Warranty (USA and Canada): SRT 3 years electronics + 2 years battery; SRTL 5 years electronics + 5 years lithium battery; Symmetra and Galaxy per-product service contract. Coordinated through our Canadian team. Shipped from Canada: see shipping policy for rates and timing.

FAQ

SRT vs SRTL: which is better?

Same online double-conversion topology and similar ratings. SRT uses SLA (APC: 3 to 5 year battery; 36-month UPS warranty). SRTL Smart-UPS Ultra uses lithium-ion (APC: 5 to 10 year battery; 60-month warranty). For 5+ year deployments and hot ambient, the SRTL means fewer battery replacements. Read Smart-UPS vs Smart-UPS RT.

What does the SRT model suffix mean?

RM = rackmount. XL = accepts external battery packs (extended runtime). The last letter gives the voltage: A = 120 V, T = 208 V, I = 230 V international. -HW = hard-wire input variant. -NC = with a network management card. So SRT5KRMXLT = Smart-UPS SRT, 5 kVA, rackmount, extended runtime, 208 V (L6-30P input, NEMA outputs).

Symmetra LX vs PX?

LX is single-phase modular 4 to 16 kVA: rack-deployable, scalable in 4 kVA power-module blocks, N+1 redundant. PX is three-phase 10 kW to 500 kW data-centre scale: power, battery, intelligence, and bypass all modular and hot-swappable. LX deploys in IT racks; PX deploys in dedicated UPS rooms.

External batteries on SRT?

Yes. SRT supports SRT48BP, SRT72BP, SRT96BP external battery packs depending on chassis voltage. APC's runtime charts give the minutes per pack.

Network management?

Network Management Card 3 with environmental monitoring (AP9641) preinstalled on SRT 5 kVA and above, per APC's data sheets; SmartSlot option on smaller SRT. Provides SNMP v1/v2c/v3, web management, Modbus, integration with VMware, Hyper-V, Linux, Windows shutdown agents.

Battery life?

SLA on SRT: 3 to 5 years climate-controlled, less in hot ambient. Lithium on SRTL: APC gives 5 to 10 years. Replace promptly when PowerChute or front-panel flags battery. When to replace UPS battery.

Canadian warranty?

Yes: Smart-UPS SRT, Smart-UPS Ultra (SRTL), Symmetra, and Galaxy factory warranty terms explicitly cover USA and Canada. Coordinated through our Canadian team. Shipped from Canada.