Example
The Varta 4022 battery together with a 1.5 m long cable and a Leonhardy 02-02.1500 plug
meet these conditions.
FM Approval
Factory Mutual Approval Standard Class Number 3611, Class I, Division 2,
Group A, B, C, D.
Temperature class: T4 at 60° C ambient temperature
WARNING
Personal injury or property damage can result.
In hazardous areas, personal injury or property damage can result if you create or break an
electrical circuit during operation of an S7-400 (for example, by means of plug-in connections,
fuses, switches).
Do not create or break live electrical circuits unless you are certain there is no danger of
explosion.
When used in FM conditions, the S7-400 must be fitted in an enclosure that corresponds to
at least IP54 in accordance with EN 60529.
NEC (National Electric Code) and CEC (Canadian Electric Code) requirements for Hazardous
Locations for battery power supply for CPUs
The backup voltage for a CPU must be supplied over a non-incendive plug connection. The
figure below shows such a plug connection.
1
2
(1)
Battery or supply voltage
(2)
CPU with "Ext. Batt." connector
Figure 1-2
Back-up voltage supply
The following conditions apply to the performance characteristics of this connection:
Voc (no load voltage) = 15 V
Vmax = 15 V
Isc (short-circuit current)= 50 mA
Imax = 50 mA
Ca = Battery/voltage supply capacity
Ci = 25 nF maximum
La = Battery/voltage supply inductance
Li = 2 mH maximum
General specifications
1.1 Standards, certificates and approvals
S7-400 Automation System Module Data
18
Reference Manual, Ausgabe 11/2016, A5E00850736-08