Section 1.0 Section 2.0 Section 3.0 Section 4.0

Section 1.0 Section 2.0 Section 3.0 Section 4.0
MCD 200 Series
Section 1.0
n Spare Parts
1.1 Main Control PCB ........................................... 3
1.2 Interface PCB ................................................... 5
1.3 SCRs ............................................................... 7
1.4 Bypass Contactors .......................................... 9
1.5 Current Transformers .................................... 11
Section 2.0
n Tests
2.1 MCD 201 Start Performance Test....................
2.2 MCD 202 Start Performance Test....................
2.3 Run Performance Test.....................................
2.4 Power Circuit Test ...........................................
2.5 Control Input Test............................................
2.6 Power Voltage Supply Test..............................
12
13
13
15
16
17
n Component Replacement Procedures
3.1 Disassembly Sequence 007~030 ..................
3.2 Exploded View MCD 201-007 ~ 030 .............
3.3 Exploded View MCD 202-007 ~ 030 .............
3.4 Disassembly Sequence 037~055 ..................
3.5 Exploded View MCD 201-037 ~ 055 .............
3.6 Exploded View MCD 202-037 ~ 055 .............
3.7 Disassembly Sequence 075~110 ..................
3.8 Exploded View MCD 201-075 ~ 110 .............
3.9 Exploded View MCD 202-075 ~ 110 ..............
18
19
20
21
22
23
24
25
26
Section 3.0
Section 4.0
MG.17.D1.02 – VLT is a registered Danfoss trademark
n Appendix
4.1 Typical Causes of SCR Damage...................... 27
4.2 Output Relay Compatibility .............................. 28
4.3 Control Input Failure ........................................ 29
1
Contents
n Warnings ........................................................... 2
Warnings
MCD 200 Series
n Warnings
Symbols used in this manual
The MCD 201 & MCD 202 contain
dangerous voltages when connected to
line voltage. Only a competent electrician
should carry out the electrical installation.
Improper installation of the motor or the
MCD 201 & MCD 202 may cause
equipment failure, serious injury or death.
Follow this manual and National Electrical
®
Codes (NEC ) and local safety codes.
The following symbols indicate items that require
special attention:
Indicates a general warning.
Indicates a high voltage warning.
Avoiding soft starter damage
Safety regulations
1.
2.
The soft starter must be disconnected from the
mains if repair work is to be carried out.
Stopping the soft starter of the does not
disconnect the equipment from the mains and
leaves one phase connected to the motor. Thus
the soft starter is not to be used as a safety
switch.
It is the responsibility of the user or the
person installing the MCD 201 & MCD
202 to provide proper grounding and
branch circuit protection according to the
®
National Electric Code (NEC ) and local
codes.
2
Please read and follow all instructions in this manual.
Additionally, take special note of the following:
1. Do not connect power factor correction
capacitors to the soft starter output. Static power
factor correction, if used, must be connected on
the mains side of the soft starter.
Electrostatic Precaution: Electrostatic
discharge (ESD). Many electronic
components are sensitive to static
electricity. Voltages so low that they
cannot be felt, seen or heard, can reduce
the life, affect performance, or
completely destroy sensitive electronic
components. When performing service,
proper ESD equipment should be used
to prevent possible damage from
occurring.
MG.17.D1.02 – VLT is a registered Danfoss trademark
Kit Part Number
(Item ID)
n Spare Parts
Main Control PCB
CV1 Models
175G9010
(990-02380-00)
175G9012
(990-02378-00)
175G9011
(990-02381-00)
175G9013
(990-02379-00)
T6 Models
Kit Part Number
(Item ID)
CV3 Models
CV1 Models
175G9014
(990-02384-00)
175G9016
(990-02382-00)
175G9015
(990-02385-00)
175G9017
(990-02383-00)
(number per unit)
1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1
Main Control PCB
(number per unit)
1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1
175G9010 (990-02380-00)
175G9011(990-02381-00)
175G9014 (990-02384-00)
175G9015 (990-02385-00)
MG.17.D1.02 – VLT is a registered Danfoss trademark
3
Spare Parts
CV3 Models
MCD 201-007-T4-xx
MCD 201-015-T4-xx
MCD 201-018-T4-xx
MCD 201-022-T4-xx
MCD 201-030-T4-xx
MCD 201-037-T4-xx
MCD 201-045-T4-xx
MCD 201-055-T4-xx
MCD 201-075-T4-xx
MCD 201-090-T4-xx
MCD 201-110-T4-xx
MCD 202-007-T4-xx
MCD 202-015-T4-xx
MCD 202-018-T4-xx
MCD 202-022-T4-xx
MCD 202-030-T4-xx
MCD 202-037-T4-xx
MCD 202-045-T4-xx
MCD 202-055-T4-xx
MCD 202-075-T4-xx
MCD 202-090-T4-xx
MCD 202-110-T4-xx
T4 Models
MCD 201-007-T6-xx
MCD 201-015-T6-xx
MCD 201-018-T6-xx
MCD 201-022-T6-xx
MCD 201-030-T6-xx
MCD 201-037-T6-xx
MCD 201-045-T6-xx
MCD 201-055-T6-xx
MCD 201-075-T6-xx
MCD 201-090-T6-xx
MCD 201-110-T6-xx
MCD 202-007-T6-xx
MCD 202-015-T6-xx
MCD 202-018-T6-xx
MCD 202-022-T6-xx
MCD 202-030-T6-xx
MCD 202-037-T6-xx
MCD 202-045-T6-xx
MCD 202-055-T6-xx
MCD 202-075-T6-xx
MCD 202-090-T6-xx
MCD 202-110-T6-xx
MCD 200 Series
Spare Parts
MCD 200 Series
175G9012 (990-02378-00)
175G9013 (990-02379-00)
175G9016 (990-02382-00)
175G9017 (990-02383-00)
4
MG.17.D1.02 – VLT is a registered Danfoss trademark
Kit Part Number (Item ID)
(number per unit)
175G9018 (990-02386-00)
175G9019 (990-02394-00)
175G9020 (990-02398-00)
1 1 1 1 1
1 1 1
1 1 1
175G9021 (990-02387-00)
175G9022 (990-02389-00)
175G9023 (990-02390-00)
175G9024 (990-02391-00)
175G9025 (990-02392-00)
175G9026 (990-02395-00)
175G9027 (990-02396-00)
175G9028 (990-02397-00)
175G9029 (990-02399-00)
175G9030 (990-02400-00)
175G9031 (990-02401-00)
1
1
1
1
1
1
1
1
1
1
1
175G9018 (990-02386-00
175G9021 (990-02387-00
175G9022 (990-02389-00)
175G9023 (990-02390-00)
175G9024 (990-02391-00)
175G9025 (990-02392-00)
MG.17.D1.02 – VLT is a registered Danfoss trademark
5
Spare Parts
Interface PCB
MCD 201-007
MCD 201-015
MCD 201-018
MCD 201-022
MCD 201-030
MCD 201-037
MCD 201-045
MCD 201-055
MCD 201-075
MCD 201-090
MCD 201-110
MCD 202-007
MCD 202-015
MCD 202-018
MCD 202-022
MCD 202-030
MCD 202-037
MCD 202-045
MCD 202-055
MCD 202-075
MCD 202-090
MCD 202-110
MCD 200 Series
MCD 200 Series
Spare Parts
175G9019 (990-02394-00)
175G9026 (990-02395-00)
175G9027 (990-02396-00)
175G9028 (990-02397-00)
175G9020 (990-02398-00)
175G9029 (990-02399-00)
175G9030 (990-02400-00)
175G9031 (990-02401-00)
6
MG.17.D1.02 – VLT is a registered Danfoss trademark
Kit Part Number
(number per unit)
175G9032
175G9033
175G9034
175G9035
175G9036
175G9037
175G9038
175G9039
175G9040
175G9041
175G9042
·
·
·
·
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
MCD 200 Soft starters may be fitted with Semikron or Eupec SCRs.
The MCD 200 SCR spare part kits may include either Semikron or Eupec SCRs
The Semikron and Eupec SCRs are fully interchangeable and can be mixed within the same
soft starter.
Connect the firing looms according to the diagrams below.
175G9032
175G9033
175G9034
175G9035
175G9036
MG.17.D1.02 – VLT is a registered Danfoss trademark
7
Spare Parts
SCRs
MCD 201-007
MCD 201-015
MCD 201-018
MCD 201-022
MCD 201-030
MCD 201-037
MCD 201-045
MCD 201-055
MCD 201-075
MCD 201-090
MCD 201-110
MCD 202-007
MCD 202-015
MCD 202-018
MCD 202-022
MCD 202-030
MCD 202-037
MCD 202-045
MCD 202-055
MCD 202-075
MCD 202-090
MCD 202-110
MCD 200 Series
MCD 200 Series
Spare Parts
175G9037
175G9038
175G9039
175G9040
175G9041
175G9042
8
MG.17.D1.02 – VLT is a registered Danfoss trademark
Kit Part Number (Item ID)
(number per unit)
175G9043 (990-02393-00)
175G9044 (350-02375-00)
175G9045 (350-02367-00)
1 1 1 1 1
1 1 1 1 1
2 2 2
2 2 2
1 1 1
1 1 1
175G9043 (990-02393-00)
175G9044 (350-02375-00)
MG.17.D1.02 – VLT is a registered Danfoss trademark
9
Spare Parts
Bypass Contactors
MCD 201-007
MCD 201-015
MCD 201-018
MCD 201-022
MCD 201-030
MCD 201-037
MCD 201-045
MCD 201-055
MCD 201-075
MCD 201-090
MCD 201-110
MCD 202-007
MCD 202-015
MCD 202-018
MCD 202-022
MCD 202-030
MCD 202-037
MCD 202-045
MCD 202-055
MCD 202-075
MCD 202-090
MCD 202-110
MCD 200 Series
MCD 200 Series
Spare Parts
175G9045 (350-02367-00)
10
MG.17.D1.02 – VLT is a registered Danfoss trademark
Current Transformers
Kit Part Number
(number per unit)
175G9046
175G9047
175G9048
2 2 2 2 2
2 2 2
2 2 2
175G9046
175G9047
175G9048
MG.17.D1.02 – VLT is a registered Danfoss trademark
11
Spare Parts
MCD 201-007
MCD 201-015
MCD 201-018
MCD 201-022
MCD 201-030
MCD 201-037
MCD 201-045
MCD 201-055
MCD 201-075
MCD 201-090
MCD 201-110
MCD 202-007
MCD 202-015
MCD 202-018
MCD 202-022
MCD 202-030
MCD 202-037
MCD 202-045
MCD 202-055
MCD 202-075
MCD 202-090
MCD 202-110
MCD 200 Series
Tests
MCD 200 Series
• Tests
The following tests and measurements can be used to
verify soft starter condition and operation.
MCD 201 Start Performance Test
This procedure tests for correct operation of the MCD
201 during start. Start mode is indicated by a flashing
Run LED (Green). This test is performed using an AC
voltage meter.
Test:
· Before commanding the MCD 201 to start,
measure the voltage across each controlled phase
(L1-T1 and L3-T3). This should be close to the
system line voltage.
· When the MCD 201 is commanded to start,
measure the voltage across each controlled phase
(L1-T1 and L3-T3). This voltage should start close
to the system line voltage and ramp down to less
than 2VAC just before the MCD 201 reaches Run
mode.
Action:
1. If measurement shows voltage across the SCR
to be equivalent to line voltage before start,
dropping to <2 VAC at run, and motor starting
problems are still experienced:
The cause of the motor starting problem is not the
MCD 201. Look for outside causes to the problem.
2. If zero voltage is measured across the SCR
before, or at the commencement of a start:
The SCR may have failed. Perform the Power Circuit
Test described later in this section.
3. If the voltage across the SCR remains at
system line voltage:
This indicates that the SCR on that phase is not firing.
The Main Control PCB, Interface PCB or connection
between them items may be faulty.
· Verify plug connections between the Main
Control PCB and Interface PCB by
- Removing and refitting the Main Control PCB
- Check for correct operation.
· If correct operation is not restored
- Replace the Main Control PCB
- Check for correct operation.
· If correct operation is not restored
- Refit the original Main Control PCB.
- Replace the Interface PCB.
- Check for correct operation.
· If correct operation is still not restored
- Replace both the Main Control PCB and the
Interface PCB.
12
MG.17.D1.02 – VLT is a registered Danfoss trademark
MCD 200 Series
Test:
· Calculate the expected motor start current by
multiplying the MCD 202 current rating by the
Motor FLC setting (Motor FLC pot) and the
Current Limit setting (Current Limit pot).
· Initiate a start and measure the actual motor start
current on phase 1 (L1/T1) and phase 3 (L3/T3).
Action:
1. If the measured start current is as expected
and motor starting problems are still
experienced:
The cause of the motor starting problem is not the
MCD 202. Check the MCD 202 settings are
appropriate and look for outside causes to the
problem.
2. If the start current is not as expected:
The SCR may have failed. Perform the Power Circuit
Test described later in this section.
The Main Control PCB, Interface PCB or connection
between them items may be faulty.
· Verify plug connections between the Main
Control PCB and Interface PCB by
- Removing and refitting the Main Control PCB
- Check for correct operation.
· If correct operation is not restored
- Replace the Main Control PCB
- Check for correct operation.
· If correct operation is not restored
- Refit the original Main Control PCB.
- Replace the Interface PCB.
- Check for correct operation.
· If correct operation is still not restored
- Replace both the Main Control PCB and the
Interface PCB.
Run Performance Test
MCD 200 soft starter incorporate internal bypass
contactors. This procedure tests the operation of the
internal bypass contactors. If the internal bypass
contactor does not operate, SCRs will eventually fail
due to thermal stress. This test is performed using an
AC voltage meter.
Test:
· While the MCD 200 is in the Off mode, measure
the voltage across each controlled phase (L1 to
T1 and L3 to T3). Line voltage should be
measured.
· Start the soft starter and listen for the bypass relay
closing. This should occur when the Run LED
(Green) changes state from flashing to on.
· Measure the voltage across each controlled phase
(L1 to T1 and L3 to T3). This should be less than
0.5 V AC.
· When a stop command is given, listen for the
bypass relay opening. If soft stop is being used,
this should occur when the Run LED (Green)
changes state from on to flashing. If no soft stop
is being used, this should occur when the Run
LED (Green) changes state from on to off.
Action:
1. If the line voltage is not measured across the
MCD 200 when in the off mode:
The Bypass Contactor is likely to be damaged and
should be replaced.
ATTENTION
The Bypass Contactors used in the MCD 200
are latching. The MCD 200 control circuits are
designed to open the Bypass Contactors even in the
event of removal or loss of control voltage. However it
is still possible that the Bypass Contactor may be
closed when there is no control supply to the MCD
200. On application of control voltage the MCD 200
will open the Bypass Contactors.
2. If Bypass Relay does not operate:
The Bypass Contactor, Main Control PCB, Interface
PCB or connection between these items may be
faulty.
·
MG.17.D1.02 – VLT is a registered Danfoss trademark
Verify plug connections between the Main
Control Module, Interface PCB and Bypass Relay
using the following method.
- Unplug the Main Control PCB from the
Interface PCB.
- Unplug the Interface PCB from the Bypass
Contactors.
13
Tests
MCD 202 Start Performance Test
This procedure tests for correct operation of the MCD
202 during start. Start mode is indicated by a flashing
Run LED (Green). This test is performed using an AC
ammeter (clip on or similar).
MCD 200 Series
Tests
·
Refit the Interface and Main Control PCBs.
Check for correct operation
Verify Bypass Contactor operation using the
following procedure
- Remove the Main Control PCB and Interface
PCBs.
- Using a 24 VDC source, momentarily apply
voltage to the Bypass Contactor control pins
as shown in the pictures below. The Bypass
Contactors are latching, so voltage needs to
be applied in both directions to fully check
operational integrity.
Bypass Control Pins : MCD 200 075, 090, 110
-
·
If the Bypass Contactor does not operate it
must be replaced.
Verify Main Control PCB and Interface PCB
operation using the following procedure.
- Replace the Main Control PCB.
- If correct operation is not restored, refit the
original Main Control PCB and replace the
Interface PCB.
- If correct operation is not restored replace
both the Main Control PCB and the Interface
PCB.
Bypass Control Pins : MCD 200 007, 015, 018, 022, 030
Bypass Control Pins : MCD 200 037, 045, 055
14
MG.17.D1.02 – VLT is a registered Danfoss trademark
MCD 200 Series
Test:
· Disconnect the incoming supply (L1, L2, L3) and
control voltage (A1, A2, A3) from the starter.
· Disconnect the motor cables (T1, T2, T3) from the
starter.
· Measure the resistance across each controlled
phase in both directions (L1-T1, L3-T3, T1-L1,
T3-L3). The resistance should be between 30 kW
and 500 kW and equal across both phases.
Tests
Power Circuit Test
This procedure tests the soft starter power circuit
including the SCR, Interface PCB and Main Control
PCB. The soft starter must be disconnected from all
power sources. This test is performed using a 500 V
DC insulation tester. Low voltage ohm meters or
multimeters are not adequate.
MOV Location : MCD 200 047, 045, 055
Action
1: If the resistance measured across any of the
two controlled phases is less than 30 kW:
The SCR should be replaced.
ATTENTION
There is no need to replace the MCD 200
Interface or Main Control PCBs just because
an SCR has been damaged. Consider replacement of
these parts only after having first replaced the
damaged SCR(s) and checked for correct operation.
The likely cause of SCR damage should also be
determined to prevent a repeat SCR failure. Analysis of
the MOVs situated on the MCD 200 Interface PCB
and connected across each controlled phase (L1T1 and L3-T3) can provide a good indication of the
mode of SCR failure.
MOV Location : MCD 200 007, 015, 018, 022, 030
MG.17.D1.02 – VLT is a registered Danfoss trademark
MOV Location : MCD 200 075, 090, 110
Overvoltage is the cause of SCR failure if the MOVs
and/or surrounding circuitry on the Interface PCB
show signs of physical damage.
Overcurrent is the likely cause of SCR failure if the
MOVs and/or surrounding circuitry on the Interface
PCB show no signs of physical damage.
Having determined the mode of the SCR failure the
cause of the damage should be considered to ensure
the damage does not reoccur.
Reliability of the modern SCRs used in the MCD 200
soft starters is such that failures attributable to faulty
manufacture are almost nil. SCR damage is almost
always caused by external influences. Often these
influences can be identified but in other cases the
identification may prove difficult or impossible because
the damaging event was temporary in nature. Refer to
4.1 of this manual for information of Typical Causes Of
SCR Damage.
2: If the resistance measured across any of the
two controlled phases is greater than 500 kW:
The Main Control PCB, Interface PCB or connection
between them items may be faulty.
15
Tests
MCD 200 Series
·
·
·
·
Verify plug connections between the Main
Control PCB and Interface PCB by
- Removing and refitting the Main Control PCB
- Check for correct operation.
If correct operation is not restored
- Replace the Main Control PCB
- Check for correct operation.
If correct operation is not restored
- Refit the original Main Control PCB.
- Replace the Interface PCB.
- Check for correct operation.
If correct operation is still not restored
- Replace both the Main Control PCB and the
Interface PCB.
Control Input Test
This procedure tests the condition of the soft starter
control inputs. This test is performed using a voltage
meter.
· Remove any external wiring from the soft starter
control inputs (N1, N2).
· Control voltage must still be connected to the soft
starter (A1 to A2 or A2 to A3).
· Measure the voltage from terminal A1 to each
control input terminal (A1 to N1 and A1 to N2).
Action:
1. If no voltage is present, the control input is
damaged. The Main Control PCB must be
replaced.
Damage to control inputs is most commonly caused
by application of incorrect control voltage by the user.
Application of incorrect control voltage is evidenced by
damage to the MOV located on the Main Control PCB.
MOV Location : Control PCB
16
MG.17.D1.02 – VLT is a registered Danfoss trademark
MCD 200 Series
·
Tests
Power Voltage Supply Test
There is no specific test procedure to check the
condition of the soft starter control voltage supply.
· If the Ready LED (Red) is off, verify that correct
control voltage is connected to the correct control
voltage input terminals.
On CV1 models, A1 to A2 voltage must be 24 V
AC or DC (+20%/-20%).On CV3 models A1 to A2
voltage must be 110 V AC to 240 V AC (+10%/15%) or A2 to A3 voltage must be 380 V AC to
440 V AC (+10%/-15%).
If the Ready LED (Red) remains off, the Main PCB
is damaged and must be replaced.
MG.17.D1.02 – VLT is a registered Danfoss trademark
17
Component Replacement
MCD 200 Series
n Disassembly Sequence 007~030
Step 1. Remove plastic lid (complete with door) from
the body of the starter using the following procedure.
· With the MCD 200 unit on its side, locate the
blade of a small flat bladed screw driver in one
of the four slots (2 each side) on the side of the
lid.
· While ensuring the screw driver blade is pushed
into the deepest part of the slot (the edge
nearest the front face of the MCD 200) tap the
screw driver so that it is driven into the starter
5-10mm. This will release the clip securing the
lid the upper body moulding.
· Repeat the above procedure for each of the
four clips.
Step 2. Remove upper body moulding using the
following procedure.
· With the MCD 200 unit on its side, locate the
blade of a small flat bladed screw driver in one
of the four slots (2 each side) on the side of the
upper body moulding.
· While ensuring the screw driver blade is pushed
into the deepest part of the slot (the edge
nearest the heatsink of the MCD 200) tap the
screw driver so that it is driven into the starter
5-10mm. This will release the clip securing the
upper body moulding to the lower body
moulding.
· Repeat the above procedure for each of the
four clips.
18
Step 3. Access is now available to all sections of the
MCD 200. Component parts can now be removed
and replaced as required.
Step 4. Reassemble the MCD 200 is reverse order.
ATTENTION
When refitting the upper body plastic
removed in Step 2 the following technique is
useful. Push in on the lower body cover at a point
next to the clip being located (1), while at the same
time pressing out and down on the upper body
cover at a point directly above the clip being secured
(2).
MG.17.D1.02 – VLT is a registered Danfoss trademark
MCD 200 Series
MG.17.D1.02 – VLT is a registered Danfoss trademark
Component Replacement
n Exploded View MCD 201-007 ~ MCD 201-030
19
Component Replacement
MCD 200 Series
n Exploded View MCD 202-007 ~ MCD 202-030
20
MG.17.D1.02 – VLT is a registered Danfoss trademark
MCD 200 Series
Component Replacement
n Disassembly Sequence 037~055
Step 1. Remove plastic lid (complete with door) from
the body of the starter using the following procedure.
· With the MCD 200 unit on its side, locate the
blade of a small flat bladed screw driver in one
of the four slots (2 each side) on the side of the
lid.
· While ensuring the screw driver blade is pushed
into the deepest part of the slot (the edge
nearest the front face of the MCD 200) tap the
screw driver so that it is driven into the starter
5-10mm. This will release the clip securing the
lid the upper body moulding.
· Repeat the above procedure for each of the
four clips.
Step 2. Remove upper body moulding using the
following procedure.
· With the MCD 200 unit on its side, locate the
blade of a small flat bladed screw driver in one
of the four slots (2 each side) on the side of the
upper body moulding.
· While ensuring the screw driver blade is pushed
into the deepest part of the slot (the edge
nearest the heatsink of the MCD 200) tap the
screw driver so that it is driven into the starter
5-10mm. This will release the clip securing the
upper body moulding to the lower body
moulding.
· Repeat the above procedure for each of the
four clips.
MG.17.D1.02 – VLT is a registered Danfoss trademark
Step 3. Access is now available to all sections of the
MCD 200. Component parts can now be removed
and replaced as required.
Step 4. Reassemble the MCD 200 is reverse order.
ATTENTION
When refitting the upper body plastic
removed in Step 2 the following technique is
useful. Push in on the lower body cover at a point
next to the clip being located (1), while at the same
time pressing out and down on the upper body
cover at a point directly above the clip being secured
(2).
21
Component Replacement
MCD 200 Series
n Exploded View MCD 201-037 ~ MCD 201-055
22
MG.17.D1.02 – VLT is a registered Danfoss trademark
MCD 200 Series
MG.17.D1.02 – VLT is a registered Danfoss trademark
Component Replacement
n Exploded View MCD 202-037 ~ MCD 202-055
23
Component Replacement
MCD 200 Series
n Disassembly Sequence 075~110
Step 1. Remove plastic cover located on the right
hand side of the frot face using the following
procedure.
· With the MCD 200 unit on its side, locate the
blade of a small flat bladed screw driver
between the lower edge of the plastic and the
metal side plate.
· Lever the cover off.
Step 3. Remove main Control PCB by lifting it up out
of the unit.
Step 4. Remove the plastic body moulding using a
flat or Torx screwdriver .
Step 2. Remove plastic lid (complete with door) from
the body of the starter using the following procedure.
· With the MCD 200 unit on its side, locate the
blade of a small flat bladed screw driver in one
of the four slots (2 each side) on the side of the
lid.
· While ensuring the screw driver blade is pushed
into the deepest part of the slot (the edge
nearest the front face of the MCD 200) tap the
screw driver so that it is driven into the starter
5-10mm. This will release the clip securing the
lid the upper body moulding.
· Repeat the above procedure for each of the
four clips.
24
Step 4. Reassemble the MCD 200 is reverse order.
MG.17.D1.02 – VLT is a registered Danfoss trademark
MCD 200 Series
MG.17.D1.02 – VLT is a registered Danfoss trademark
Component Replacement
n Exploded View MCD 201-075 ~ MCD 201-110
25
Component Replacement
MCD 200 Series
n Exploded View MCD 202-075 ~ MCD 202-110
26
MG.17.D1.02 – VLT is a registered Danfoss trademark
MCD 200 Series
fuses do not operate quickly enough to protect SCRs
from short circuits.
Typical Causes of SCR Damage
SCR damage is generally caused by one of three
mechanisms, overcurrent, overvoltage or
overtemperature. Before replacing damaged SCRs it is
important to identify the cause of damage if at all
possible. The following list details some of the
common problems.
Overcurrent
· Cable fault on output of soft starter.
· Motor fault.
· Start current and/or start time exceeds the soft
starter ratings.
· Starts per hour exceed the soft starter rating.
Line contactors: SCRs are most vulnerable to damage
caused by overvoltage when they are in the off state
and have voltage applied to their input terminal. In this
condition the SCR is blocking the full line voltage. Use
of a line contactor to remove voltage from the SCR
input when the starter is in the off state eliminates the
chance of SCR damage due to overvoltage.
Note that when the soft starter is operating in Run
mode, the SCRs are bypassed by the internal bypass
relay. In this situation, the soft starter is immune to
damage caused by voltage fluctuations.
Overvoltage
· Power supply transient or surge.
· Lightening strike (direct or indirect) on power
supply.
· Motor fault.
· Loose connection in power circuit, before or after
the starter.
· Power factor correction connected to the output
of the soft starter.
· Over corrected bulk power factor correction on a
lightly loaded system causing severe ringing
voltages.
In most cases, failure caused by Overvoltage will be
indicated by physical damage to the MOVs (2). These
are located on the underside of the Interface PCB.
Overtemperature
· Blocked heatsinks or restricted ventilation.
· Inadequate ventilation.
· Excessive ambient temperatures.
If the internal bypass relay does not operate, SCRs will
eventually fail due to thermal stress.
Protecting SCRs
The SCRs used in modern soft starters are rugged
and provide reliable operation in most industrial
environments without the need for additional
protection. However the potential for SCR damage
can be reduced by use of semiconductor fuses and/or
line contactors.
Semiconductor fuses: Use of semiconductor fuses
reduces the potential for SCR damage caused by
short circuits on the output of the starter. Note that
protection systems such as circuit breakers or HRC
MG.17.D1.02 – VLT is a registered Danfoss trademark
27
Appendix
• Appendix
Appendix
MCD 200 Series
Output Relay Compatibility
Overview
The MCD 201 soft starter has one fixed (Main
Contactor) output relay.
The MCD 202 soft starter has one fixed (Main
contactor) and one programmable (Trip/Run) output
relay.
These PCB mount relays are often used for line
contactor control.
Recent advances in contactor design have lead to
many manufacturers using electronic contactor coils.
Initially these coils may appear to meet the
specifications of the PCB mount relays. However, in
some instances these electronic contactor coils have a
high initial inrush current due to the internal switch
mode power supply circuitry. This can have a
damaging effect on the PCB mount relays if the
contactor coil is switched directly.
Solution
Before using an MCD 200 soft starter PCB mount
output relay for direct switching of an electronic
contactor coil, consult the contactor
manufacturer/supplier to see if this is advisable.
Certain contactor manufacturers (eg Klockner-Moeller)
state that you cannot use PCB mount relays for direct
switching of their electronic contactor coils.
If this is the case, there are two solutions:
1.
Use a MCD 200 soft starter output relay to control
a slave relay. This slave relay can then be used to
directly switch the electronic contactor coil circuit.
2.
Some contactor brands have a volt free electronic
input (low voltage/low current). If this is available,
the MCD 200 output relay can be wired directly
into this input for contactor control.
28
MG.17.D1.02 – VLT is a registered Danfoss trademark
MCD 200 Series
Appendix
Control Input failure
Overview
The MCD 200 soft starter can be operated by external
2 wire or 3 wire control signals.
External contacts/switches are configured and wired
into control input terminals N1 and N2.
Cause of Control Input failure
External contacts/switches operating the control
inputs must be rated for the control voltage being
used and a continuous current of 100mA.
Incorrect configuration and wiring of the external
contacts/switches to the control input terminals N1
and N2 may cause damage.
If long cable runs are used, wiring must be twisted pair
or shielded cable and must be separated from AC
power cables (minimum distance 300mm).
Testing for Control Input failure
Refer to the Control Input Tests detailed in Section 2.6
of this manual.
$"65*0/
Application of incorrect voltages to the
control inputs may cause equipment
damage and necessitate replacement of
the Main PCB.
ATTENTION
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MG.17.D1.02 – VLT is a registered Danfoss trademark
29
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