Kühn Controls


Part numbering of RELECO relays series MRC, QRC, IRC


Basic identification principle (type designation code):

C n(n) - T X y zz /...V Ref. nnnn

Normal industrial relay code "C" is a normal industrial relay code
Relays with code "R" are used for railway series.
Basic type refers to the product line Basic type refers to the product line
C2 = MR-C, Universal 8 pin plug-in mount
C3 = MR-C, Universal 11 pin plug-in mount
C4 = MR-C, Square base, 4 contacts 10 A
C5 = MR-C, Square base, 3 contacts 16 A
C7 = QR-C, miniature 2 contacts 10 A
C9 = QR-C, miniature 4 contacts 5 A
C10 = IR-C, Interface 1 contact 10 A
C12 = IR-C, Interface 2 contacts 5 A
CSS = IR-C, Solid state relay
Relay type Relay type
A = Standard (general-purpose) contact
E = Sensitive drive with 500 mW coil power
G = Refers to a NO contact
H = Single-point contact + twin contact load to signal current circuit for switching state feed back.
  Mixed contact configuration
M = Relay with highly effective neodimium blow magnet for fast quenching of the arc.
  This relay is particularly suitable for high DC loads.
N = Sensitive drive 800mW coil power
R = Code for remanence relays, drive-specific ID
S = Sensitive drive with 250 mW exciter input
T = Twin contact for signal and control circuit
W = With tungsten contact for maximum switch-on currents
Number of contacts Number of contacts
1, 2, 3 or 4
Definition of contact material Definition of contact material
0 = Contact standard AgNi (except relays C9)
3 = Contact 3μ Au
4 = Contact for sensitive relays, flashed of 0,2μ Au
5 = Contact Ag SnO2
8 = Contact 10μ Au
9 = Contact, flashed of 0,2μ Au
low level - C9 and relays with twin contacts:
1 = Contact flashed of 0,2μ Au (standard in relays C9)
2 = Contact 10μ Au
Describes the options Describes the options
D = Integrated freewheeling diode
F = Integrated freewheeling diode and series diode e.g. for common alarm circuits
R = RC connection for the coil
X = Electric position indicating device with LED
B = Bridge rectifier
Special requirements:
H = Orange button. No lockable function
N = Black button. No function
P = Printing board pins
E = Lap transparent cover
Z = Close transparent cover
T = Close transparent cover (lamp)
M = Close transparent cover (lamp + button)
if other requirements, please consult.
Nominal coil voltage or current specification Nominal coil voltage or current specification
AC … V, DC … V, UC … V (AC/DC)
AC … A, DC … A
The relays are generally available for voltages of 6 V up to DC 220 V/AC 240 V (AC 400 V) or UC 6 up to 48 V.
This information is printed of the cover of the relay or at the coil (for old relays).
Additionally, you can recognise the coil voltage by color of the lockable test button.
Current relays available on request.
Ref. nnnn Ref. nnnn
Relays with a reference number are versions with special (e.g. customised) features.
These features may relate to special test criteria, tolerances or other properties.
Availability of such relays may be limited to certain customers or applications.
Electrical circuit according DIN Electrical circuit according DIN
Approvals, international standards and conformities Approvals, international standards and conformities

Codification of the lockable test button

The RELECO relays have five different colours for an easier identification of coil voltage

red button red standard: 230VAC
dark red button dark red: others AC voltages
grey button grey: universal current UC(AC/DC)
blue button blue standard: 24VDC
dark blue button dark blue: others DC voltage
orange button If you don't want to have the lockable function,
you can use the orange "orange-push button"
black button A black blanking plug is available if you don't want a test button.


Product range
Releco offers a wide range of relay types and versions and associated bases and accessories.

Standard (general-purpose) relay, MRC series
35 x 35 mm round plug-in relay, 8- or 11-terminals multipole connector according to IEC 67 with 2 or 3 contacts up to 10 A and different contact types and contact materials.
Standard relay 35 x 35 mm with flat blade connectors with up to 4 contacts and up to 16 A with 3 contacts.

Miniature industrial relay, QRC series
21 x 28 mm series with up to 4 contacts and up to 10 A with 1 or 2 contacts.

Interface relay, IRC series
Overall width 13 mm with up to 2 electromechanical contacts, or fully electronic switches.

Special relays, remanence relays
While "normal" relays are monostable, i.e. they return to the idle state when the excitation is switched off, remanence relays are bistable, i.e. the current switching state is retained irrespective of the excitation.
Relays of this type are available in different versions.

Electronic relay, CSS series
In the IRC series different electronic DC or AC relays up to 3 A are available.
For AC relays a distinction is made between synchronously (zero crossing) and asynchronously switching versions.
For switching transformer loads we recommended using asynchronously switching semiconductor switches.
For incandescent lamp loads etc. synchronously switching switches are ideal for avoiding high switch-on currents.

Suitable bases are available for the different relay series for DIN rail mounting or panel mounting.
In addition, retaining clips are available for the relays, some of which are included in the scope of supply.
Suitable bridges for cost-saving wiring in series are also available.

You want more informations about part numbering of RELECO, Please send us a fax: +49 (0)7082- 94 00 01, or email to: Inquiry to Kühn Controls... we help you...

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