Half-Inch Diameter Process Sealed Rotaries
Series MR
Distinctive Characteristics
Low profile body of MRF model accommodates space limitations
required for PCB mounting. For the MRA and MRK bushing
mount models, the range of behind panel body depths is .323”
to .669” (8.2mm to 17.0mm).
Positive detent mechanism for distinct feel and audible feedback.
Metal bushing and housing construction increases durability.
Adjustable stopper plate allows 2–12 position settings.
High contact reliability achieved by the self-cleaning
contact mechanism.
Break-before-make contact timing with sliding contacts in
MRA and rotary contactor disk in MRF and MRK models.
Interior housing seal and molded-in PC terminals, plus shaft
rubber o-ring on MRF and MRK and polyamide cover on MRF
model, allow cleaning after automated soldering.
Exterior rubber washer and double flatted bushing on MRA and MRK
give protection in splashproof applications.
Actual Size
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05-08
Half-Inch Diameter Process Sealed Rotaries
Series MR
General Specifications
Electrical Capacity (Resistive Load)
For MRA:
For MRF or MRK:
250mA @ 125V AC
0.4VA maximum @ 28V AC/DC maximum
(Applicable Range 0.1mA ~ 0.1A @ 20mV ~ 28V)
Note: Find additional explanation of operating range in Supplement section.
Other Ratings
Contact Resistance:
Insulation Resistance:
Dielectric Strength:
Mechanical Life:
Electrical Life:
Range of Operating Torque:
Contact Timing:
Indexing:
10 milliohms maximum for MRA; 50 milliohms maximum for MRF & MRK
100 megohms minimum @ 500V DC
1,000V AC minimum for 1 minute minimum for MRA
500V AC minimum for 1 minute minimum for MRF & MRK
30,000 operations minimum
10,000 operations minimum
0.02 ~ 0.07Nm for MRA; 0.005 ~ 0.02Nm for MRF & MRK
Nonshorting (break-before-make)
MRA – self-cleaning, sliding contact; MRF & MRK – self-cleaning, rotary contactor disk
30°
Materials & Finishes
Shaft:
Stopper Plate:
Bushing/Housing:
Movable Contacts:
End Contacts & Terminals:
Common Contacts & Terminals:
Base:
Brass with nickel plating
Steel with zinc plating for MRA & MRK; polyamide cover with stopper for MRF
Zinc alloy with zinc plating
Copper with silver plating for MRA; phosphor bronze with gold plating for MRF & MRK
Brass with silver plating for MRA; phosphor bronze with gold plating for MRF & MRK
Brass with silver plating for MRA; phosphor bronze with gold plating for MRF & MRK
Diallyl phthalate for MRA; fiberglass reinforced polyamide for MRF & MRK
Environmental Data
Operating Temperature Range:
Humidity:
Vibration:
Shock:
–10°C through +70°C (+14°F through +158°F)
90 ~ 95% humidity for 96 hours @ 40°C (104°F)
10 ~ 55Hz with peak-to-peak amplitude of 1.5mm traversing the frequency range
& returning in 1 minute; 3 right angled directions for 2 hours
50G (490m/s
2
) acceleration (tested in 3 right angled directions, with 3 shocks in each direction)
Installation
Mounting Torque:
Cap Installation Force:
.686Nm (6.08 lb
•
in)
19.6 ~ 29.4N (4.41 ~ 6.61 lbf) for MRA & MRK
Processing
Soldering Time & Temperature:
Cleaning:
Wave Soldering for MRA: See Profile A in Supplement section.
Wave Soldering for MRF & MRK: See Profile B in Supplement section.
Manual Soldering for MRA: See Profile A in Supplement section.
Manual Soldering for MRF & MRK: See Profile B in Supplement section.
Automated cleaning recommended. Stopper plate, as well as washers for MRA & MRK, must be in
place to maintain automated cleaning. See Cleaning specifications in Supplement section.
Standards & Certifications
UL Recognition
or CSA Certification:
MRA, MRF, & MRK models have not been tested for UL recognition or CSA certification.
These switches are designed for use in a low-voltage, low-current, logic-level circuit.
When used as intended in a logic-level circuit, the results do not produce hazardous energy.
NKK Switches • email: sales@nkkswitches.com • Phone (480) 991-0942 • Fax (480) 998-1435 • www.nkkswitches.com
05-08
Half-Inch Diameter Process Sealed Rotaries
TYPICAL SWITCH ORDERING EXAMPLE
Series MR
MR
A
206
POLES & CIRCUITS
112
206
403
SP with 2-12 Positions
DP with 2-6 Positions
4P with 2-3 Positions
A
B
C
A
KNOBS
Plain Black
Small Color Tipped
Large Color Tipped
ACTUATORS & TERMINALS
A
F
K
Shaft Actuated with PC Terminals
Low Profile Screwdriver Actuated
with PC Terminals
Low Profile Shaft Actuated with
PC Terminals
COLORS
For Plain Knob
No
Code
A
B
C
Black
For Color Tipped
Black
White
Red
Yellow
Green
Blue
Gray
DESCRIPTION FOR TYPICAL ORDERING EXAMPLE
E
F
G
H
MRA206-A
Shaft Actuated with
Plain Black Knob
DP with 2-6
Adjustable Positions
PC Terminals
ACTUATORS & TERMINALS
A
Shaft Actuated
with PC Terminals
F
Low Profile
Screwdriver Actuated
with PC Terminals
K
Low Profile
Shaft Actuated
with PC Terminals
12
9
11
10
2
3
6
4
5
12
7
89
2
1
12
11
10
(2.3)
.091
(3.15) Dia
.124
2
(3.5)
.138
1C
12
11
1 0
(10.0)
.394
(0.5)
.020
Thk = (0.25)
.010
Shaft
Terminal
NKK Switches • email: sales@nkkswitches.com • Phone (480) 991-0942 • Fax (480) 998-1435 • www.nkkswitches.com
10
11
1
M
R
-
12
2
(0.8)
.031
(3.15) Dia
.124
(1.0)
.039
(0.5)
.020
Thk = (0.25)
.010
(3.5)
.138
1 C
M
R
-
K
1
1
2
9
0
12
11
1
11
10
9
(2.3)
.091
(3.15) Dia
.124
(3.5)
.138
(10.0)
.394
(0.5)
.020
Thk = (0.25)
.010
Slotted for
Screwdriver
Terminal
Shaft
Terminal
05-08
Half-Inch Diameter Process Sealed Rotaries
POLES & CIRCUITS
Pole
Model
MRA112
SP
MRF112
MRK112
MRA206
DP
MRF206
MRK206
MRA403
4P
MRF403
MRK403
Number of Positions
2–12
2–12
2–12
2–6
2–6
2–6
2–3
2–3
2–3
Stopper Settings
2, 3, 4, . . . 12
2, 3, 4, . . . 12
2, 3, 4, . . . 12
2, 3, 4, 5, 6
2, 3, 4, 5, 6
2, 3, 4, 5, 6
2, 3
2, 3
2, 3
Number of Terminals
1 COM, 12 LOAD
1 COM, 12 LOAD
1 COM, 12 LOAD
2 COM, 12 LOAD
2 COM, 12 LOAD
2 COM, 12 LOAD
4 COM, 12 LOAD
4 COM, 12 LOAD
4 COM, 12 LOAD
1
1
1
Series MR
Schematics
A
2 3 4 5 6
A
7 8 9 10 11 12
B
2 3 4 5 6
A
B
1
2 3 4 5
C
D
6
2 3 1
2 3
1
2 3 1
2
3
POSITION SETTING FOR MRA, MRF, & MRK MODELS
Each switch is supplied with the stopper set for the maximum number of positions allowed for that model. Prior to installation,
the desired position setting should be made. Contact factory for continuous rotation.
MRF Models
1. Remove the protective cover from the switch body.
2. Turn the shaft counterclockwise to the extreme left by using a screwdriver.
3. Inside the cover is a magnifying lens which would be positioned over the
number which is to be the maximum position used; when the cover is then
snapped into the switch, the projection beside the lens fits into the correct
hole for setting the stop.
Protective Cover
Lens
6
4
5
12
Projection
7
2
3
89
2
1C
12
11
1 0
MRK & MRA Models
1. Using the actuator knob, turn the shaft
counterclockwise to the extreme left. If
the shaft is not turned counterclockwise
to the extreme left, proper setting can-
not be achieved. At this extreme posi-
tion, the white line on the knob points
to the number 1 position shown on the
side of the switch.
2. Remove the knob from the shaft and
loosen the nut far enough to allow rais-
ing the stopper plate, plus washer(s),
for resetting to the desired position.
3. Note the position numbers on the side
of the switch; these correspond to the
terminal numbers and stopper holes.
Insert the stopper in the hole numbered
for the maximum desired number of
stop settings. Satisfactory switch func-
tioning cannot be assured if the stopper
plate is not properly positioned.
4. Tighten the nut (beveled side up) firmly
against the stopper plate.
Standard Mounting Hardware
Packaged Loose with Each Switch:
Hex Face Nut
Locking Ring
Lockwasher
Rubber Ring (MRK)
Factory Assembled:
Hex Nut
Stopper Plate
Metal Washer (MRA)
Rubber Washer
12
2
1 C
M
R
-
K
1
1
2
9
0
12
11
1
11
10
9
NKK Switches • email: sales@nkkswitches.com • Phone (480) 991-0942 • Fax (480) 998-1435 • www.nkkswitches.com
10
11
1
M
R
-
12
9
11
10
2
1
12
11
10
05-08
Half-Inch Diameter Process Sealed Rotaries
TYPICAL SWITCH DIMENSIONS
MRA • PC Terminals
M6 P0.75
(0.8) Dia Typ
.031
Series MR
2 Pole
(3.0) Dia
.118
1 Pole
(3.0) Dia
.118
4 Pole
(3.0) Dia
.118
D
4
4
C
12
A
3
1
2
6
A
3
1
2
3
A
1
2
Keyway
(3.15) Dia
.124
(16.0) Dia
.630
(2.3)
.091
(1.0)
.039
(10.0)
.394
(5.0)
.197
(17.0)
.669
(6.0)
.236
(10.0)
.394
30°
Ty
(9.5) Dia
.374
p
30°
Ty
(9.5) Dia
.374
p
3
1
2
B
B
5
30°
Ty
(9.5) Dia
.374
MRA112
MRF • PC Terminals
(0.8)
.031
6
7
8
1 Pole
Cover
(0.25) Typ
.010
2 Pole
4 Pole
8
7
3
4
5
21
5
(12.0) Dia
.472
9
6
3
B
2
1
3
B
2
1
1
10
4
6
3
21
D
(4.2)
.165
(14.0) Dia
.551
(8.2)
.323
(0.5) Typ
.020
(3.5)
.138
15
ϒ
Ty
p
yp
15
ϒ
T
yp
15
ϒ
T
(12.6) Dia
.496
(12.6) Dia
.496
(12.6) Dia
.496
MRF403
MRK • PC Terminals
M6 P0.75
(0.25) Typ
.010
1 Pole
2 Pole
4 Pole
8
9
7
3
6
5
B
2
1
3
D
2
1
B
2
1
3
21
(12.0) Dia
.472
(2.3)
.091
(0.5) Typ
.020
(10.0)
.394
(5.5)
.217
(10.1)
.398
(3.5)
.138
1
10
5
4
6
3
Keyway
(3.15) Dia
.124
15
ϒ
Ty
p
yp
15
ϒ
T
(12.6) Dia
.496
yp
15
ϒ
T
(12.6) Dia
.496
(12.6) Dia
.496
MRK112
MRK devices are designed to be panel mounted. Installation without panel mounting will affect reliability.
FOOTPRINTS
Single Pole
MRA112
Double Pole
MRA206
Four Pole
MRA403
Single Pole
MRF112
MRK112
7
Double Pole
MRF206
MRK206
(0.8) Dia Typ
.031
15
ϒ
Ty
p
2
3
4
4
6
2 1 A
5
Four Pole
MRF403
MRK403
(0.8) Dia Typ
.031
1
2
3
D
1
2
3
3
2 1 A
180
ϒ
6
5
4
3
2
A
9
10
11
1
12
6
5
4
3
2
A
3
B
4
5
1
6
3
2
C
A
3
2
3
B
D
1
3
1
2
6
5
4
3
30
ϒ
Ty
p
8
2
30
ϒ
Ty
p
7
(3.0) Typ
.118
(9.5) Dia
.374
1
(3.0) Typ
.118
(9.5) Dia
.374
1
2
(3.0) Typ
.118
(9.5) Dia
.374
(0.8) Dia Typ
.031
8
B
9
10
11
12
6
5
1
B
2
1
C
3
1
(12.0) Dia
.472
(12.0) Dia
.472
30
ϒ
Ty
p
(1.0) Dia Typ
.039
30
ϒ
Ty
p
(1.0) Dia Typ
.039
30
ϒ
Ty
p
(1.0) Dia Typ
.039
15
2 1 A
3
ϒ
Ty
p
15
ϒ
Ty
p
15
ϒ
Ty
p
NKK Switches • email: sales@nkkswitches.com • Phone (480) 991-0942 • Fax (480) 998-1435 • www.nkkswitches.com
3
5
1
32
A
2
1
2
3
1
A
6
1
2
3
A
2
1
3
21
A
6
7
8
9
3
10
11
4
5
1
2
p
ϒ
15
ϒ
15
ϒ
15
30
ϒ
6
30
ϒ
30
ϒ
3
A
2
1
1
A
2
1
1
9
10
11
12
1
2
90
ϒ
21
5
5
C
4
4
3
3
Typ
15
ϒ
ϒ
15
ϒ
15
30
ϒ
6
5
30
ϒ
C
2
1
4
3
4
(12.0) Dia
.472
05-08
