Siemens S5-135U/155U appendix 6ES5 955-3NC42 6ES5 955-3NF42 Protection and monitoring

Central Controllers and Expansion Units Power Supply Units

6ES5 955-3NC42

6ES5 955-3NF42

Protection and monitoring

Voltage Monitor

Overvoltage shutdown Vo/p1

Undervoltage signal Vo/p1

Current limiting for overload

Test sockets for Io/p1 on front plate

Signaling section

Green LED: ª5V o.k.º for Vo/p1

Monitors voltage for <14 V and >16 V

6 V $ 5%

4.75 V + 3%

1.0 to 1.2 Io/pN1

(3 V ¢ 18 A)

linearity range 0.5 V/2.8 A to 3 V/18 A

Signals for SIMATIC S5,

relays ªFan Warning, Fan Alarm, Warningº 250 V/3 A

LED lights up if

4.75V < Vo/p1

Monitors voltage for <14 V and >16 V

6 V $ 5%

4.75 V + 3%

1.0 to 1.2 Io/pN1

(3 V ¢ 40 A)

linearity range 0.5 V/6.6 A to 3 V/40 A

Signals for SIMATIC S5,

relays ªFan Warning, Fan Alarm, Warningº 250 V/3 A

LED lights up if

4.75V < Vo/p1

Output 2

Rated output voltage Vo/pN2

Rated output current Io/pN2

Total current X2 and front terminals

Ripple

Spikes

Protection and monitoring

DC 24 V (+ 25%, -12.5%)

1 A

1 A max.

v1% of Vo/p2

v2% of Vo/p2

DC 24 V (+ 25%, -12.5%)

2.8 A

2.8 A max.

v1% of Vo/p2

v2% of Vo/p2

Current limiting for overload	1 to 1.3 Io/pN2
Green LED: ª24V o.k.º for Vo/p2	LED lights up if
	Vo/p2 > 19.9 V to 21.1 V
Maximum permitted capacity	0.2 mF

Output 3

1 to 1.3 Io/pN2

LED lights up if

Vo/p2 > 19.9 V to 21.1 V

0.8 mF

Rated output voltage Vo/pN3

Rated output current Io/pN3

Ripple

Spikes

Maximum permitted capacity

DC 15 V ($ 5%)

0.5 A

v1% of Vo/p3

v3% of Vo/p2

100 mF

DC 15 V ($ 5%)

2 A

v1% of Vo/p3

v3% of Vo/p2

750 mF

Protection and monitoring

Overvoltage shutdown Vo/p1

Current limiting for overload

Green LED: ª15V o.k.º for Vo/p3

Maximum permitted capacity

17 V $ 5%	17 V $ 5%
1 to 1.5 IAN3	1 to 1.5 IAN3
During startup 4 IAN3 for 40 ms
LED lights up if 14.2 to 14.7 V <	LED lights up if 14.2 to 14.7 V <
Vo/p3 < 16.1 to 17.9 V	Vo/p3 < 16.1 to 17.9 V
10 mF	10 mF

System Manual	4-55
C79000-G8576-C199-06