Skip to main content
Log in
Siemens 6AG1931-2FC21-7AA0 — PLCs (Programmable Logic Controllers)

Siemens 6AG1931-2FC21-7AA0 SIPLUS PS DC UPS module 40 A

MPN6AG1931-2FC21-7AA0
NRND

Siemens 6AG1931-2FC21-7AA0 — now in phase-out and being discontinued. Supplied from remaining channel stock; full specifications, lifecycle and same-series options are below.

$684.53Ref. price · indicative, final on quote
Siemens 6AG1931-2FC21-7AA0 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jun 2026

Specifications

6AG1931-2FC21-7AA0 key specifications
ParameterValue
Type of energy storagewith batteries
Type of electrical connectionscrew-type terminals
Input voltage range22 ... 29 V DC
Voltage curve at inputDC
Formula for output voltageVin - approx. 0.5 V
Supply voltage at DC rated value24 V
Output voltage in buffering mode at DC19 ... 28.5 V
Voltage increase time of the output voltage typical360 ms
Input current at rated input voltage 24 v rated value40 A; + approx. 2.6 A with empty battery
Adjustable response value voltage for buffer connection22 ... 25.5 V; Adjustable in 0.5 V increments
Adjustable response value voltage for buffer connection preset22.5 V
Reverse polarity protection against input voltage polarity reversalYes

All specifications

6AG1931-2FC21-7AA0 additional specifications
ParameterValue
At rated output voltage for rated value of the output current typical28.6 W
Peak current42 A
Charging current1 A, 2 A
Adjustable charging current maximum notefactory setting approx. 2 A
Supplied active power typical960 W
Design of the mains power cut Bridging-ConnectionDependent on connected battery and load current, see selection table battery module and mains buffering times as well as the relevant important information notes!
Depth of the enclosure125 mm
Width of the enclosure102 mm
Height of the enclosure125 mm
Product feature of the enclosure housing can be lined upYes
Design of the interfacewithout
Product component PC interfaceNo
Installation altitude at height above sea level maximum6 000 m
Ambient temperature in horizontal mounting position during operation-25 ... +70; with natural convection
Ambient condition relating to ambient temperature - air pressure - installation altitudeIn case of operation at altitudes of 2000 - 6000 m above sea level: Output power derating of -7.5 %/1000 m or reduction of the ambient temperature by 5 K/1000 m
Ambient temperature during storage and transport-40 ... +85
MTBF at 40 °C522 739 h
CE markingYes
Reference code according to IEC 81346-2RB
Top50 mm
Left0 mm
Right0 mm
Bottom50 mm
At input24 V DC: 2 screw terminals for 0.33 ... 10 mm²/22 ... 7 AWG
At output24 V DC: 2 screw terminals for 0.33 ... 10 mm²/22 ... 7 AWG
Rated value40 A
MountingSnaps onto DIN rail EN 60715 35x7.5/15
In buffering modeBuffered mode: LED yellow (Bat), floating changeover contact "OK/Bat" to setting "Bat"; Prewarning battery voltage < 20.4 VDC: LED red (alarm), floating changeover contact "Alarm/Bat" to setting "Alarm"; Energy storage > 85%: LED green (Bat > 85%), floating NO contact "Bat > 85" closed
Other informationSpecifications at rated input voltage and ambient temperature +25 °C (unless otherwise specified)
In normal operation0 ... 40 A
Protection class IPIP20
For normal operationNormal operation: LED green (OK), floating changeover contact "Bat/OK" to setting "OK" ("OK" means: Voltage of the supplying power supply unit is greater than cut-in threshold set at the DC UPS module); Lack of buffer standby: LED red (alarm), floating changeover contact "Alarm/Bat" to setting "Alarm"; Battery replacement required: LED red (alarm) flashing with approx. 0.25 Hz, floating changeover contact "Alarm/Bat" switching with approx. 0.25 Hz; Energy storage > 85%: LED green (Bat > 85%), floating NO contact "Bat > 85" closed; Permissible contact current capacity: DC 60 V/1 A or AC 30 V /1 A
Electrical accessoriesBattery module
For emitted interferenceEN 55022 Class B
For interference immunityEN 61000-6-2
Startup delay time typical1 s
For rechargeable battery module24 V DC: 2 screw terminals for 0.33 ... 10 mm²/22 ... 7 AWG
Operating resource protection classClass III
In buffering mode at DC rated value24 V
In normal operation at DC rated value24 V
For control circuit and status message10 screw terminals for 0.5 ... 2.5 mm²/20 ... 13 AWG
Galvanic isolation between input and outputNo
In case of operation on rechargeable battery typical33.6 W
Chemical resistance to commercially available cooling lubricantsYes; incl. diesel and oil droplets in the air
Reverse polarity protection against energy storage unit polarity reversalYes
Product conformity of the coating qualification and performance of electrical insulating compound for printed board assemblies according to IPC-CC-830AYes; Conformal Coating, Class A

Product details

Overview

The 6AG1931-2FC21-7AA0 is a Siemens SIPLUS PS DC UPS module rated for 40 A continuous current, accepting a 24 V DC input and delivering a buffered output with a switching current of 42 A.

This module bridges a 24 V DC power supply and a battery energy storage, providing uninterrupted DC power during mains dips or failures. In normal operation the green OK LED and the floating changeover contact indicate the supply voltage is above the cut-in threshold. When the input drops, the module switches to buffered mode — the yellow Bat LED and the OK/Bat contact signal the transition. A prewarning threshold at 20.4 V DC triggers the red alarm LED and the Alarm/Bat contact, giving the control system time for an orderly shutdown. The module also reports energy storage above 85% via a dedicated green LED and a normally-open contact. Rated at 40 A continuous input current with a 42 A switching capability, the module handles the inrush of downstream loads and battery charging simultaneously. The output voltage follows the input minus approximately 0.5 V, so the load sees nearly the same rail voltage during normal operation. A typical startup delay of 1000 ms allows the upstream supply to stabilise before the module engages the load.

The module snaps onto a DIN rail per EN 60715 (35 x 7.5/15) and uses screw-type terminals for field wiring. Its enclosure measures 13.5 x 15.00 x 11.00 cm and weighs 1100 g, occupying a single unit width on the rail. The IP20 rating suits clean, dry cabinet environments. Ambient temperature range of -40 to +85 °C and 100% humidity tolerance (including diesel and oil droplets in the air) make it suitable for harsh industrial and outdoor-adjacent installations. Altitude derating applies above 6000 m.

MPN
6AG1931-2FC21-7AA0