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Safety relay - output extension 4004K/SNE 4004KV

Output expansion with relay for base devices in safety applications
• Stop category 0 and 1 according to EN 60204-1 (see “Notes”)
• Applications up to safety category 4 according to EN 954-1
(see “Notes”)
• Single-channel or two-channel control
• SNE 4004K: 4 enabling current paths, undelayed (NO contact)
3 signaling current paths, undelayed (NC contact)
• SNE 4004KV: 4 enabling current paths, OFF-delayed (NO contact)
3 signaling current paths, OFF-delayed (NC contact),
Time buffering

• Expansion of a base device’s enabling current paths
• Contact expansion in safety equipment


SNE 4004K

Supply voltage to the SNE devices is routed via an enabling current path of a base device. When the supply voltage is applied relays K1 and K2 switch into the ON position. After this switch-on phase the four enabling current paths 13 /14, 23 / 24, 33 / 34, 43 / 44 (of the SNE 4004K) or 17/18, 27/ 28, 37/ 38, 47/ 48 (of the SNE 4004KV) are closed and the feedback current path Y1/ Y2 is open. This is displayed through two LEDs that are assigned to relays K1 and K2.When the enabling current paths of the base device are opened through the operation of the emergency stop button, relays K1 and K2 on the SNE 4004K switch back into the OFF position. The enabling current paths open and the feedback current path closes.Feedback current path Y1/ Y2 prevents the base device from switching on again beforeK1 or K2 releases.

SNE 4004KV

The functions of this device correspond to those of the SNE 4004K.The SNE 4004KV is available with the  following four OFF-delay times tR1: 0.5 s; 1 s; 2 s and 3 s. The device has an OFF-delay time that is enabled through capacitors.This causes the OFF-delay time R1 to elapse completely even in case of failure of
the power supply (A1/ A2). It cannot be deleted before it has elapsed. Upontiming-out the relays K1 and K2 switch into the OFF position. OFF-delay timesof > 0 s correspond to stop category 1.

SNE 4004K-A and SNE 4004KV-A

The functions of these devices correspond to those of the SNE 4004K or SNE 4004KV. Devices with the -A identification in their type designation are equipped with four removable pluggable terminals (see the K4-2 dimension diagram).This feature allows a quick installing/removing operation. The terminal locations are coded and not interchangeable
Functional diagram
A1/A2 supply voltage
Y1/Y2 feedback path
13/14,23/24,33/34,43/44, LED K1 ,LED K2
51/52 61/62
tA = response time
tR2 = release time
A1/A2 supply voltage
Y1/Y2 feedback path
17/18,27/28,37/38,47/48, LED K1 ,LED K2

tA = response time
tR1 = release time
tM = minimum ON time
Proper use

The device can only be used as expansion device for safety switching devices.
• The stop and safety categories achieved by the SNE 4004K / KV always depend
on the categories of the base device. The category of the expansion device
cannot exceed that of the base device. By using the SNE 4004KV max.
category 3 according to EN 954-1 can be achieved.
• The expansion relays K1 and K2 are controlled via one or two enabling current
paths, depending on the required level of safety.
• The devices can be combined with all safety switching devices (base devices).
The feedback current path Y1/ Y2 must be wired to the reset or feedback loop of
the base device.
• The device and the contacts must be protected with max. 6 A utilization
category gG or through circuit breakers with trigger characteristic B or C.
• For connecting magnetic switches with reed contacts or sensors
with semiconductor outputs the peak input current must be considered
(see “Technical data”).
• The devices must be installed in a control cabinet with a protection degree
of at least IP 54.


Connection scheme
Dimensions [mm]
SNE 4004K/KV SNE 4004K-A/KV-A
Technical data SNE 4004K/SNE 4004KV
Function according to EN 60204-1
Emergency stop expansion relay