MS/MD Series
aPPlication
A range of aluminium electrolytic capacitors
specifically designed for a.c. operation
which help to start the motor by providing a
leading current to the auxillary winding. The
capacitor is not permanently connected to
the winding of the motor and is switched off
after starting, usually automatically.
60/70°C
RoHS
Compliant
• intermittent ac motor starting
• 6.3 mm double amp tags (quick connect types)
• vdE approved to En 60252-2
basic dEsign
Capacitors for this application are designed
for itermittent duty only, and capable of
withstanding the a.c. voltage applied to
the motor during starting. The capacitor
construction comprise either double anode
or O-style (double anode and floating
cathode) windings and are housed in a
moulded plastic case. The MD series is VDE
approved to EN 60252-2 for the defined
ratings.
sPEcification
standards
capacitance range
capacitance tolerance
rated voltage u
r
surge voltage u
s
Endurance life time
+70°c, 1.1u
r
+60°c, 1.1u
r
DIN EN 60252-2:- AC Motor Capacitors - Part 2 : Motor Start Capacitors
25 µF to 750µF
±10% or -0% +25%
120V - 330Vac 50Hz
1.25 x U
R
MD types 500 hrs
(at specified duty cycle)
MS types 500 hrs
(at specified duty cycle)
End of Life requirement:
ΔC/C
< ±10%
cos
ϕ
< 0.2
shelf life
temperature range
2 years
-20°C to +70°C MD types
-20°C to +60°C MS types
dimensions mm
case code
d1 ±0.5
d2 ±0.5
lmax
AA
AB
AC
38
38
38
39
39
39
75
90
116
vdE approvals to En 60252-2
rated voltage
capacitor type
capacitance (µf)
30
40
50
60
70
80
90
100
120
125
220v
md
(note 1)
AA
AA AB
AA AB
AA AB
AB
AB AC
AC
AC
AC
AC
260v
md
(note 2)
AB
AB
AB
AB
AB
note 1: duty cycles approved;
220V @ SD=3 & ED=1.7%
280V @ SD=1 & ED=0.55%
300V @ SD=1 & ED=0.1%
note 2: duty cycles approved;
260V @ SD=3 & ED=1.7%
330V @ SD=1 & ED=0.55%
general approval notes;
• valid for both ±10% and -0 +25% tolerance.
• valid for intermediate capacitance values in increments of 1µF
between 30µF and 100µF and in increments of 5µF between
100µF and 125µF.
ms / md motor starting capacitors
120vac
type number
min. cap. max. cap.
(µf)
(µf)
25
25
85
90
120
130
25
25
85
90
120
130
325
360
460
510
670
750
325
360
460
510
670
750
tolerance
can size
(mm)
38x75
38x75
38x90
38x90
38x116
38x116
38x75
38x75
38x90
38x90
38x116
38x116
duty cycle
@ 120v rms
@ 150v rms
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
---MS12AAMA1STD
---MS12AAMK1STD
---MS12ABMA1STD
---MS12ABMK1STD
---MS12ACMA1STD
---MS12ACMK1STD
---MD12AAMA1STD
---MD12AAMK1STD
---MD12ABMA1STD
---MD12ABMK1STD
---MD12ACMA1STD
---MD12ACMK1STD
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
0.55%
0.55%
0.55%
0.55%
0.55%
0.55%
220vac
type number
---MS22AAMA1STD
---MS22AAMK1STD
---MS22ABMA1STD
---MS22ABMK1STD
---MS22ACMA1STD
---MS22ACMK1STD
---MD22AAMA1STD
---MD22AAMK1STD
---MD22ABMA1STD
---MD22ABMK1STD
---MD22ACMA1STD
---MD22ACMK1STD
min. cap. max. cap.
(µf)
(µf)
30
30
40
40
55
65
30
30
40
40
55
65
65
70
90
100
130
150
65
70
90
100
130
130
tolerance
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
can size
(mm)
38x75
38x75
38x90
38x90
38x116
38x116
38x75
38x75
38x90
38x90
38x116
38x116
duty cycle
@ 220v rms
@ 280v rms
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
0.55%
0.55%
0.55%
0.55%
0.55%
0.55%
260vac
type number
min. cap. max. cap.
(µf)
(µf)
25
25
35
35
50
55
25
25
30
35
45
50
55
60
75
85
110
125
50
55
70
80
100
115
tolerance
can size
(mm)
38x75
38x75
38x90
38x90
38x116
38x116
38x75
38x75
38x90
38x90
38x116
38x116
duty cycle
@ 260v rms
@ 330v rms
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
1.67%
---MS26AAMA1STD
---MS26AAMK1STD
---MS26ABMA1STD
---MS26ABMK1STD
---MS26ACMA1STD
---MS26ACMK1STD
---MD26AAMA1STD
---MD26AAMK1STD
---MD26ABMA1STD
---MD26ABMK1STD
---MD26ACMA1STD
---MD26ACMK1STD
*
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
-0% +25%
±10%
0.55%
0.55%
0.55%
0.55%
0.55%
0.55%
capacitance code
e.g. 030=30µf, 120=120µf
tEchnical data
dual voltage rating
The MD range of capacitors is designed
with a dual voltage rating. The lower voltage
rating relates to a duty cycle of 1.67% and
the upper voltage rating relates to a duty
cycle of 0.55%.
Power factor
The tangent of the loss angle for motor start
capacitors shall not exceed 0.1 and shall be
calculated as follows:
Tan
δ
= W =
true watts
V x I apparent watts
duty cycle
The standard rating is 1.67% or 1/60th full
time and corresponds to a maximum duty
of 20 starts, each of three seconds duration
per hour. It is expressed as 3/1.67 (a 3 minute
cycle with 1.67% duration during which the
capacitor may be energised). If the same
capacitor is to be used for a duty cycle of
60 starts per hour the cycle duration will
be 1 minute. The operation time per cycle
will then have to be reduced to 1.67% of 1
minute (i.e. 1 second). Alternative duty cycles
are available on request.
Presence of run capacitor
When the motor is fitted with both starting
and run capacitors, consideration should be
given to fitting of the appropriate discharge
resistor to the starting capacitor. This is
to protect the run capacitor from damage
through discharge of the starting capacitor.
container form
Cylindrical mouldings, meeting creepage
and clearance distances, according to IEC
60335-1 and flammability ratings according
to UL94-V1.
BHC and Evox Rifa
Electrolytic Capacitors
14
ms / md motor starting capacitors
tEchnical data
discharge resistors
A discharge resistor may be fitted to a
motor start capacitor to prevent electrical
overstress of the capacitor and or for safety
reasons. In accordance with BS5267 and
IEC 60252, the resistor value should be such
that it reduces the voltage on the capacitor,
from the line voltage to less than 50V within
60 secs.
The resistor value may be approximated as
follows:
T
R (kW) max. =
Rated capacitance µF
rated voltage
(d.c.)
120
220
260
280
330
t
50000
32000
30000
28000
26000
value (kohms)
5.6
15
33
56
82
100
wattage
2W
2W
0.5W
1W
2W
1W
Part numbEring
Pos 1–15
0
1
8
2
0
3
m
4
s
5
2
6
2
7
a
8
b
9
m
10
a
11
1
12
s
13
t
14
d
15
080
ms
22
ab
m
a
1
std
variants, Pos. 13-15
STD=standard design, all other codes are
customer specific.
terminal code, Pos. 12
1 = Double amp tag
2 = special variant
motor start
capacitance tolerance, Pos. 11
A = -0% +25%, K = ±10%
manufacturing style, Pos. 10
M = Moulded case
case code, Pos. 8-9
AA = 38x75, AB = 38x90, AC = 38 x 116
rated voltage (rms), Pos. 6-7
12 = 120Vac, 22 = 220Vac, 26 = 260Vac
type code, Pos. 4-5
MS = Motor start single rating
MD = Motor start dual rating
capacitance code, Pos. 1-3
080 = 80µF, 120 = 120µF
