WARPP WTR-400 User manual

OPERATION MANUAL FOR
ARC WELDING RECTIFIER
Model WTR-400
WARPP ENGINEERS PVT. LTD.
B-1005, Western Edge II, Near Metro Mall, Off. Western
Express Highway, Borivali (E), Mumbai-400 066.
Tel: [phone]/74. Fax: [phone].
E-mail:[email protected] Web Site:www.warpp.co.in

INDEX
Sr. No. Description Page No.
1 Introduction 1
2 Installation 2
3 Operation 2
4 Maintenance 3
5 Safety 3
6 Trouble shooting 4
7 Spare part List 10
ILLUSTRATIONS
1) Control Circuit Wiring Diagram 6
2) Power Circuit Wiring Diagram 7
3) Installation Diagram 8

INTRODUCTION.
This manual describes the equipment, installation, operation, safety, and
maintenance of WARPP make DC arc welding rectifiers. Tease welding
equipments are designed for manual metal arc and manual TIG welding
application in heavy duty fabrication. Simple design and rugged construction
makes it most ideal for maintenance free operation. This equipment is mounted
on four wheel chassis with two fixed wheels in the front and two revolving wheels
at the back side.
This equipment consists of a three phase step down transformer along with
three phase magnetic amplifier (Transductor) and three phase silicon diode
rectifier. The welding current is varied by varying the current in the DC coils of
the transductor. This current is obtained by a control transformer and an auto
transformer along with a single phase silicon diode rectifier. The transformer
steps down 415 Volts input supply to a voltage around 100 volts which is fed to
the rectifier via the autotransformer. The output of the rectifier is given to the DC
coils of the transductor.By varying the autotransformer setting the current fed to
the DC coils of the transducor varies and hence the actual welding current varies
accordingly. The autotransformer is calibrated for exact output welding current.
Main transformer is provided with primary tapping to work on 380/415/440 volts
input supply. All the components of the equipment is cooled by an single phase
fan. A simple change over of output cables allows the operator to use either
straight OR reverse polarity.
1

INSTALLATION.
1) The machine should be kept in a relatively clean and dry place and a minimum
of 0.3 meters of space should be left around the equipment for easy circulation of
air.
NOTE THAT THE MACHINE DRAWS FRESH AIR FROM THE FRONT AND
FORCES IT THROUGH THE BACK.
2) A separate mains switch should be provided for this equipment. The mains
switch should be of good quality with proper contacts. The switch should be
easily accessible to the operator.
3) Three core 7/20 gauge cables can be used for the input supply connection.
The equipment should be properly earthed and all the electrical connections
should be firm and tight. Power connection point is provided on the back cover of
the equipment.
4) The equipment must be connected to a proper earth point.
OPERATION.
1) After installation of the equipment connect the holder to the negative and job
earth cable to the positive output of the equipment. (This connection is termed as
Straight polarity. Reverse polarity can be made by interchanging the job earth
and holder cables).
2) Switch on the mains Supply.
2

3) Put the ON-OFF Switch on front panel of the equipment in ON position this will
a) Start the cooling FAN
b) Energies the main transformer
c) Puts on the MAINS indicator.
4) Set the current regulator to the required output current.
5) Connect the JOB EARTH cable firmly to the job.
6) Hold the required electrode in the holder.
7) Strike an arc by scratching the electrode to the job.
MAINTENANCE.
1) Switch OFF the mains supply.
2) Open the top cover
3) Clean the equipment by removing dust by a blower.
4) Lubricate the fan bearings in regular intervals.
CAUTION: SWITCH OFF THE SUPPLY BEFORE OPENING THE EQUIPMENT.
SAFETY PRECAUTION:
1) Welding light is dangerous to the eyes as it has ultraviolet rays. Always use
welding screen with proper glass while welding.
2) Wear leather gloves, Apron and leather shoes while welding.
3) Keep the welding area relatively clean and free from inflammable materials
4) Use fully insulated holder.
5) Do not touch the electrode with the bare skin.
3

TROUBLE SHOOTING.
TROUBLE CAUSE REMEDY
Mains supply is
switched ON and ON-
OFF switch is put to
ON position but welder
does not come ON.
i) Three phase supply is not
proper
ii) Mains Switch is not proper.
iii) Control fuse is blown off
i)Wait till the three phase
power is available
ii) Check for the proper
electrical contacts in the
mains switch.
iii) Replace the control fuse.
(This fuse is mounted on
the control transformer.
Equipment comes on
but the welding current
varies.
i)The mains connection is not
proper.(Loose connection)
ii) Current regulator is not
working properly. (Either the
carbon brush is weared out
OR it is not making the proper
contact.
i) Check the mains for
proper and firm
connection.
ii) Replace the carbon
brush.
The equipment comes
ON but the control
fuse blows.
i) Control Transformer
Damaged
ii) Fan Damaged
iii) Current Regulator
Damaged
iv) Control Rectifier
Damage
i) Check & Replace
ii) Check & Replace
iii) Check & Replace
iv) Check & Replace
Welding arc is
sluggish.
i) Welding current is low.
ii) Loose connection
iii) Input supply is less.
I) Increase the current.
ii) Make firm connection.
iii) Check the input
Supply.
and use proper tapping
(380/415/440) by changing
the jumper on the main
transformer

the equipment give
minimum current but
the current doesn’t
increases
i) Current regulator burnt OR
not working.
ii) Control transformer is
dead.
iii) Control rectifier is failed.
iv) Control fuse is blown.
i) Check & Replace
ii) Check & Replace
iii) Check & Replace
iv) Check & Replace
Welding arc is not
smooth and spatter is
more
i) Current setting is too high.
ii) DC polarity used for that
particular electrode is not
right.
iii) Diodes have failed.
i) Reduce the current.
ii) Use proper polarity
(Interchange the polarity
and check).
iii) Replace the diode OR
Diodes.
Mains fuse blows i) Short circuit in the primary
of the main transformer.
ii) Short circuit in main diodes
i) Remove the short circuit.
ii) Replace the diodes.