motortronics MWH Series Installation and operation manual

MWH Series
Solid State
Motor Winding Heater
10 to 80 Amps
INSTALLATION & START-UP
MANUAL
REV 4
6091101MN
MOTORTRONICS
Solid State AC Motor Control
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

Table of Contents
Chapter 1: General Information .................. 1
1.1Introduction
1.2Features
1.3Specifications
1.4RecievingandUnpacking
1.5Dimensions
Chapter 2: Installation ................................. 4
2.1Wiring
Chapter 3: Operation ................................... 7
Chapter 4: Diagrams ................................... 8
4.1 MWH 10 Amp Model
4.2 MWH 25 Amp Model
4.3 MWH 50 Amp Model
4.4 MWH 80 Amp Model
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 1 -
MWH Series 10 - 80 Amps
1.1 Description
The Motortronics MWH Series Solid State Motor
Winding Heater is designed to prevent condensa-
tion build-up by applying a low level current to the
AC motor windings when the motor is in the “off”
condition. Motor windings are susceptible to con-
densation formation each time the motor is stopped
and the windings’ temperature drops below the dew
point. Over a period of time this condensation build-
up can degrade the insulation of the windings and
cause a short circuit when the motor is started. The
same problem can occur when motors are not op-
erated for an extended period of time. This is espe-
cially true for damp and humid locations.
1.2 Features
Fully Automatic Operation
The Motortronics
MWH Series is designed for fully
automatic operation. It turns on approximately one
minute after power is applied to the system. When
the motor is started the MWH is instantly turned off.
The MWH turns back on approximately one minute
after the motor is turned off.
Overload Sensings
With the optional overload sensing, the MWH can
be disabled automatically when a motor overload
trip occurs. The heater will go back on-line auto-
matically after the overload is reset. This prevents
additional motor heating when a trip occurs provid-
ing faster motor cool down after a thermal overload
trip condition.
LED Status Display
Indicator lights on the MWH inform the operator of
the unit stats. The POWER ON indicator shows that
the power is on and both of the MWH fuses are
good. The ENABLE indicator shows that the motor
Chapter 1 - General Information
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 2 -
MWH Series 10 - 80 Amps
is off and the MWH control interlock is closed. The
OUTPUT ON indicator shows that the MWH is sup-
plying power to the motor windings.
Designed for Safety
The MWH Series is supplied in a compact open
chassis design. Optional NEMA 1 enclosures are
also available. The front cover of the unit is fiber-
glass insulation material which shields against acci-
dental contact with electrically live parts.
1.3 Specifications
Adjustments: Output voltage is factory set to pro-
vide sufficient power to the motor to maintain a +5°
to 10° C differential above ambient temperature
which is suitable for most applications. This adjust-
ment can be used to trim the control as required for
each application.
Fusing: Two fuses protect the MWH.
Transient Protection: An RC snubber circuit across
the SCR protects it from rapid rate of change in the
system voltage. A metal oxide varistor (MOV) pro-
tects the unit against voltage spikes on the line.
208V 240V 480V 575V
MWH-10 10 3 - 40 5 - 50 10 - 100 15 - 125
MWH-25 25 50 - 100 60 - 125 125 - 250 150 - 300
MWH-50 50 125 - 200 150 - 250 300 - 500 350 - 600
MWH-80 80 250 - 300 300 - 400 600 - 800 700 - 900
MODEL MOTOR HORSEPOWER RANGE
MAX
AMP
RATING
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 3 -
MWH Series 10 - 80 Amps
.
1.5 Dimensions
1.4 Receiving and Unpacking
Unpacking - Carefully unpack the unit from the ship-
ping carton and inspect it for shipping damages. Im-
mediately report any damages to the carrier.
Mounting - Select mounting location and make sure
ambient temperature does not exceed operating
range limits given in specifications. Allow for suffi-
cient clearance on all sides of the unit.
HWDHWD
MWH-10 6.2 4.5 6 11 7 7
MWH-258 6 6117 7
MWH-50 10 8 7.9 15 10 8
MWH-80 10 8 8 20 10 10
NEMA1 (N)
MODEL OPEN PANEL
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 4 -
MWH Series 10 - 80 Amps
2.1 Wiring
Connection diagrams illustrate typical wiring connec-
tions. Use 75° C minimum wires.
Note: All wiring
must comply with local codes, regulations and
ordinances.
WARNING!
Do not service equipment with voltage applied.
Unit can be the source of fatal electrical shocks.
1. Mount the MWH on a vertical panel with the line
connection (L1, L2) at the top. Proper orientation
is required to achieve proper convention cooling of
the solid state power device (SCR).
2. Remove the front cover of the winding heater for
access to the power and control connections.
3. Recommended fuse and power wire sizes for
MWH:
2.0 - Installation
F1 F2
10 14 Class T 600V 15 A Class CC 20A Time Delay
25 8 Class T 600V 30 A Class T 600V 70A
50 6 Class T 600V 60 A Class T 600V 100A
80 2 Class T 600V 100 A Class T 600V 150A
MAXIMUM
MWH AMP
WIRE SIZE
TYPE THHN
REPLACEMENT FUSE
MWHL1L2T1T2
10 20 20 45 20
25 20 50 50 50
50 20 50 50 50
80 50 50 50 50
TORQUE LB/IN
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 5 -
MWH Series 10 - 80 Amps
4. Connect L1 and L2 on the MWH to L1
and L2 on the magnetic contactor us
ing the wire size recommended for your
unit. (See Connection Diagram on right).
5. Connect T1 and T2 to the load side of
the magnetic contactor before the over
load relay heater elements. Do not con-
nect to starter terminals T1 and T2. Use
the wire size recommended for your
unit.
6. If your system utilizes a heater off-on
switch, connect it in series with normally
closed auxiliary contact on the motor
starter to the terminals labelled “SW”.
Use AWG 16 wire for the circuit.
7. If your system does not utilize a heater
off-on switch, connect the normally
closed auxiliary contact directly to the
terminals labeled “SW” (TB1). Note:
The cover of the motor winding heater
depicts the connection diagram (See
page 5).
8. If required, connect the normally open
contact from the motor overload to the
overload connection as shown on the
wiring diagram.
9. Replace the cover when all connections
have been completed and checked.
Wiring Diagram for units rated at 25 Amps
Wiring Diagram for units rated at
10, 50 and 80 Amps
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 6 -
MWH Series 10 - 80 Amps
10. Included with each unit are two self-adhesive warn-
ing labels. Attach one warning label in a conspicu-
ous place on the motor junction box and the other
on the outside of the starter enclosure.
11. If the motor winding heater is to be parallelled with
a soft start, the customer must provide an isolation
contactor between the output of the MWH and the
motor as shown in the figure below.
Wiring Diagram to
Parallel the MWH unit
with a Soft Start
Sample Warning Label
WARNING
THIS MOTOR IS EQUIPPED WITH A MOTOR
WINDING HEATER. VOLTAGE IS PRESENT
AT MOTOR TERMINALS EVEN WHEN
MOTOR STARTER IS OPEN. BEFORE SERVICING
MOTOR OR MOTOR WIRING ALWAYS
DISCONNECT MAIN POWER AHEAD
OF MOTOR STARTER.
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 7 -
MWH Series 10 - 80 Amps
1. Apply line voltage to the system. The “Power On”
LED on the MWH should light. If the “Power On”
LED does not light, it is an indication of a blown fuse
or improper connections. Do not proceed until this
is corrected.
2. If the motor starter is off and the “SW” circuit is
closed, then the “Enable On” LED will be on. The
MWH will turn on automatically in approximately 1
minute.
3. The “Output On” LED will turn on when the MWH
begins to apply voltage to the motor.
4. The output voltage to the motor is factory set for 8%
to 9% of the line voltage. (Measured with an RMS
AC Voltmeter) Maximum range of this adjustment
is approximately 15% of line voltage.
Note: Caution must be used when adjusting the
output. Too high a setting may cause excessive
heating in the motor.
5. During initial start-up monitor the output current to
the motor. Use a standard AC clamp-on ammeter.
Output current must not exceed the rating of the
motor winding heater unit.
6. When the motor is starter the MWH automatically
shuts off. It will remain off until the motor is turned
off. The MWH will then turn on after approximately
1 minute.
3.0 - Operation
LED Placement
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 8 -
MWH Series 10 - 80 Amps
4.1 MWH 10A Model
4.0 - Diagrams
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 9 -
MWH Series 10 - 80 Amps
4.2 MWH 25A Model
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 10 -
MWH Series 10 - 80 Amps
4.3 MWH 50A Model
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 11 -
MWH Series 10 - 80 Amps
4.4 MWH 80A Model
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]

MOTORTRONICS
- 12 -
MWH Series 10 - 80 Amps
Motortronics warrants its products to be free from
defects in material and/or workmanship for a period of
one year from the date of installation of a maximum of
18 months from the date of shipment as indicated by the
unit’s date code. The company reserves the right to
repair or replace any malfunctioning units under war-
ranty at their option. All warranty repairs must be
performed by the Company factory, or on site by factory
authorized service firms or personnel approved by the
Company.
Solid state controls have different operating characteris-
tics from those of electro-mechanical equipment.
Because of these differences and the wide variety of
applications for solid state controls, each application
designer must verify that the solid state equipment is
acceptable for his application. In no event will
Motortronics be responsible or liable for indirect or
consequential damages resulting from the use or
application of this equipment. The diagrams and illustra-
tions in this document are included solely for illustrative
purposes. Because of the number of different applica-
tions, Motortronics can not be responsible or liable for
actual use based on the examples or diagrams.
Warranty
Buy: www.ValinOnline.com | Phone [phone] | Email: [email protected]