Lotos Technology LTP7500CNC User manual

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LTP7500CNC
OWNER’S MANUAL
Carefully read the operation manual prior to using, installing and maintaining the electric
welding machine
The contents of this manual may be revised without prior notice and without obligation.
This instruction manual is issued on 1st May 2021. Rev 01
Conforms with EMC
Directives:

IMPORTANT
Save This Manual
You will need the manual for safety warnings and
precautions, assembly instructions, operating and
maintenance procedures, parts list and diagram.
Keep your invoice with this manual. Write invoice
number and date of purchase on the inside of the
manual. Keep the manual and invoice in a safe and
dry place for the future.
Operation Manual
Carefully read the operation manual prior to using,
installing and maintaining the electric welding
machine for the purpose of preventing damages
such as fire, electric shock and etc. from occurring.
Please keep the manual as a reference in the future.

CONTENTS
Safety………………………………………………………………………………………………………………..1
Specification.......…………………………………………………………………………………………………6
Main Parameter………………………………………………………………………………………………………8
Quick Setup…………………………………………………………………………………………………………11
Installation……………………………………………………………………………………………………………..13
Operation…………………………………………………………………………………………………………..15
Maintenance…… … … … … … … … … … … … ………………………………………… … … … … …….24
Troubleshooting..............................................................................................................................................25
Reference..........................................................................................................................................................26
Consumables....................................................................................................................................................27
EC DECLARRATION OF CONFORMITY
We hereby declare that our machines for industrial and professional use as stated
below Type: LTP7500CNC
Conforms with EMC Directives:
73/23/EEC and 89/336/EEC
European Standard: EN/IEC60974
Please read and understand this instruction manual carefully before the installation and
operation of this equipment.
The contents of this manual may be revised without prior notice and without obligation.

1
SAFETY WARNINGS AND PRECAUTIONS
PLEASE READ AND
UNDERSTAND THE FOLLOWING
SAFETY HIGHLIGHTS. BE
SURE THAT A L L INSTALLATION,
OPERATION, MAINTENANCE A N D REPAIR
PROCEDURES ARE PERFORMED ONLY BY
QUALIFIED INDIVIDUALS. A R C AN D TIG
WELDING CAN BE HAZARDOUS. PROTECT
YOURSELF AND OTHERS FROM POSSIBLE
SERIOUS INJURY OR DEATH. KEEP
CHILDREN A W A Y . PACEMAKER USERS
SHOULD CONSULT WITH THEIR DOCTOR
BEFORE OPERATING.
WHEN USING THE WELDER, ALL
BASIC SAFETY PRECAUTIONS
SHOULD ALWAYS BE FOLLOWED
T O REDUCE THE RISK OF PERSONAL
INJURY AND DAMAGE TO EQUIPMENT.
READ ALL INSTRUCTIONS BEFORE
USING THIS WELDER.
Keep work area clean. Cluttered areas
invite injuries.
Observe work area conditions. Do not
use machine or power tools in damp or wet
locations. Do not expose to rain. Keep work
area well-lit. Do not use electrically-
powered tools in the presence of flammable
gases or liquids.
Keep children away. Children must never
be allowed in the work area. Do not let them
handle machines, tools or extension cords.
Store idle equipment. When not in use,
tools must be stored in a dry location to
inhibit rust.
Always lock up tools and keep them out of
the reach of children.
Do not force tool. It will do the job better
and safer at the rate for which it w a s
intended. Do not use inappropriate
attachments i n an attempt to exceed the
tool capacity.
Use the right tool for the job. Do not
attempt to force a small tool or attachment
to do the work of a larger industrial tool.
There are certain applications for which this
welder w a s designed. Do not modify this
welder, and do not use this welder for any
other purposes for which it was not intended.
Dress properly. Do not wear loose clothing
or jewelry as they can be caught in moving
parts. Protective, flame retardant,
electrically non-conductive clothing and
non-slip footwear are recommended when
working. Wear restrictive hair netting to
contain long hair.
Use eye and ear protection. Always wear
ANSI-approved, Arc-shaded, impact safety
face shield (welding helmet). Always use a
full-face shield when welding. Always wear
ANSI-approved eyewear under face shield,
and while in the workplace. Wear a NIOSH-
approved dust mask or respirator when
working around metal, chemical dusts,
fumes and mists.
Do not over reach. Keep proper footing
and balance at all times. Do not reach over
or across running machines.
Maintain tools with care. Keep tools sharp
and clean for better and safer performance.
Follow instructions for lubricating and
changing accessories. Inspect tool cords
periodically and, i f damaged, have them
repaired by an authorized technician. The
handles must be kept clean, dry, and free
from oil and grease at all times.
Disconnect power. Unplug tool when not
in use.

2
Remove adjusting keys and wrenches.
Check that keys and adjustment wrenches
are removed from the welder and work area
before plugging in.
Avoid starting unintentionally. Be sure
the switch is in the off position when not in
use and before plugging in. Do not carry any
tool with your finger on the trigger, whether
it is plugged in or not.
Stay alert. Watch what you are doing. Use
common sense. D o not operate any tool
when tired.
Check for damaged parts. Before using
any tool, any part that appears damaged
should be carefully checked to determine
that it would operate properly and perform
its intended function. Check for alignment
and binding of moving parts; any broken
parts or mounting fixtures; and any other
condition that may affect proper operation.
Any part that is damaged should be properly
repaired or replaced by a qualified
technician. Do not use the tool if any switch
does not turn on and off properly.
Guard against electric shock. Prevent
body contact with grounded surfaces such
as pipes, radiators, ranges and refrigerator
enclosures.
Replacement parts and accessories.
When servicing, use only identical
replacement parts. Use of any other parts
w i l l void warranty. Only use accessories
intended for use with this welder. Approved
accessories are available from
www.uwelding.com.
Do not operate tool if under the influence
of alcohol or drugs. Read warning labels
on prescriptions to determine i f your
judgment or reflexes are impaired while
taking drugs. If there is any doubt, do not
operate the welder.
Maintenance. For your safety, service and
maintenance should be performed regularly
by a qualified technician.
 Use proper size and type extension cord.
If an extension cord is required, it must be
of the proper size and type to supply the
correct current to the welder without heating
up. Otherwise, the extension cord could
melt and catch fire, or cause electrical
damage to the welder. This welder requires
use of an extension cord of 20Amps
minimum capability up to 30 feet, with a wire
size rated at 12 A W G . Longer extension
cords require larger size wire. If you are
using the welder outdoors, use an extension
cord rated for outdoor use, signified by “WA”
on the jacket. Performance of this welder
may vary depending on condition in local
line voltage. Extension cord usage may also
affect welder performance.
The warnings, cautions and
instructions discussed in this
instruction manual cannot cover
all possible conditions and situations that
may occur. It must be understood, by the
operator, that common sense and caution
are factors, which cannot be built into this
product, but must be observed at all times
by the operator.

3
ARC WELDER SAFETY WARNINGS
AND PRECAUTIONS
Warning: This product, when used for
welding and similar applications, produces
chemicals known to cause cancer and birth
defects (or other reproductive harm).
ELECTRIC SHOCK can be fatal
The electrode and work (or
ground) circuits are electrically
“hot” when the machine is on. Do
not touch these “hot” parts with your bare skin
or w e t clothing. Protective clothing should be
hole free, dry and ANSI approved. Wear dry,
hole-free gloves to insulate hands.
Do not permit electrically live parts, cables,
or electrodes to contact skin, clothing or
gloves.
This unit draws enough current to cause
serious injury and or death.
Before turning the welder on, check the
welder gun to be sure that there are no
protruding screw heads and that all
insulation is secure.
Insulate yourself from work and ground
using dry insulation. Make certain the
insulation is large enough to cover your full
area of physical contact with work and
ground.
Always be sure the work cable makes a
good electrical connection with the metal
being cut. The connection should be as
close as possible to the area being cut.
Ground the work metal to be cut to a good
electrical (earth) ground.
Maintain the welding torch, work clamp,
power cable and cutting machine in a safe
operating condition. Replace damaged
insulation wherever it is needed.
Never dip the electrode in water for cooling.
When working above floor level, use a
safety belt to protect yourself from a fall
should you get a shock.
Plasma cutting may produce
fumes and gases hazardous to health. Avoid
breathing these fumes and gases. When cutting,
keep your head out of the fume. Use enough
ventilation and/or exhaust at the arc to keep
fumes and gases away from the breathing zone.
In confined spaces or in some circumstances,
outdoors, a respirator may be required.
Additional precautions are also required when
cutting on galvanized steel.
 Do not cut in locations near chlorinated
hydrocarbon vapors coming from
degreasing, cleaning or spraying operations.
The heat and rays of the arc can react with
solvent vapors to form phosgene, a highly
toxic gas and other irritating products.
Read and understand the manufacturer’s
instructions for this equipment and the
consumables to be used, including the
material safety data sheet (MSDS) and
follow your employer’s safety practices.
MSDS forms are available from
your welding distributor or from
the manufacturer.
The EMF field
that is
generated during arc welding may interfere with
various electrical and electronic devices such
as cardiac pacemakers.
Anyone using such devices should consult
with their physician prior to performing any
electric welding operations.
Exposure to EMF fields while welding may
have other health effects, which are not
known.
FUMES & GASES can be
dangerous
ELECTRIC&MAGNETIC
FIELDS may be dangerous

4
ARC RAYS can burn
 Avoid eye and body
damage. Arc rays and infrared
radiation can cause injury to the
eyes and burn the skin. Wear ANSI-
approved eye and body protection. Do not
allow viewing by visitors without proper eye
and body protection.
Use a shield with the proper filter and cover
plates to protect your eyes from sparks and
the rays of the arc when plasma cutting or
observing open arc plasma cutting.
Use suitable clothing made from durable
flame-resistant material to protect your skin
and that of your helpers from the arc rays.
Protect other nearby personnel with suitable,
non-flammable screening and/or warn them
not to watch the arc nor expose themselves
to the arc rays or to hot spatter or metal.
WELDING SPARKS can
cause fire or explosion
Avoid eye and body damage.
Arc rays and infrared radiation
can cause injury to the eyes
and burn the skin. Wear ANSI-approved eye
and body protection. Do not allow viewing by
visitors without proper eye and body protection.
Use a shield with the proper filter and cover
plates to protect your eyes from sparks and
the rays of the arc when plasma cutting or
observing open arc plasma cutting.
Use suitable clothing made from durable
flame-resistant material to protect your skin
and that of your helpers from the arc rays.
Protect other nearby personnel with suitable,
non-flammable screening and/or warn them
not to watch the arc nor expose themselves
to the arc rays or to hot spatter or metal.
CYLINDER may explode if
damaged
Use only compressed gas
cylinders containing the correct
shielding gas for the process used and
properly operating regulators designed for
the gas and pressure used. All hoses,
fittings, etc. should be suitable for the
application and maintained in good
condition.
Always keep cylinders in an upright position
securely chained to an undercarriage or
fixed support.
Cylinders should be located:
Away from areas where they may be struck
or subjected to physical damage.
A safe distance from arc welding or cutting
operations and any other source of heat,
sparks, or flame.
Never allow any electrically “hot” parts to
touch a cylinder.
Keep your head and face away from the
cylinder valve outlet when opening the
cylinder valve.
Valve protection caps should always be in
place and hand tight except when the
cylinder is in use or connected for use.
T u r n off input power using the
disconnect switch at the fuse
box before working on the equipment.
 Install equipment in accordance with the
local codes and the manufacturer’s
recommendations.
Ground the equipment in
accordance with the
manufacturer’s
recommendations. Keep away from moving
parts such as fans.
 Keep all doors, panels, covers and safety
guards closed and securely in place.
ELECTRICALLY POWERED
EQUIPMENT can be
dangerous
MOVING P A R T S can cause
injury

5
CALIFORNIA PROPOSITION 65 WARNINGS
Welding or cutting equipment
produces fumes or gases which
contain chemicals known to the
State of California to cause birth defects and, in
some cases, cancer. (California Health & Safety Code
Section 25249.5 et seq.)
Battery posts, terminals and related
accessories contain lead and lead
compounds, chemicals known to the
State of California to cause cancer and birth
defects or other reproductive harm. Wash
hands after handling.
For Gasoline Engines:
Engine exhaust contains
chemicals known to the State of
California to cause cancer, birth
defects, or other reproductive harm.
For Diesel Engines:
Diesel engine exhaust and
some of its constituents are
known to the State of California
to cause cancer, birth defects,
and other reproductive harm.
PLEASE READ THIS OPERATION MANUAL CAREFULLY AND
THOROUGHLY BEFORE ATTEMPTING TO OPERATE THIS MACHINE.
KEEP THIS MANUAL HANDY FOR QUICK REFERENCE. PAY CLOSE
ATTENTION TO THE SAFETY INSTRUCTIONS PROVIDED FOR YOUR
OWN PROTECTION.

6
SPECIFICATIONS
❖ GENERAL DESCRIPTION
THANK YOU! You had options for other plasma cutter machines and you chose LOTOS
LT P 7500CNC plasma cutter. We appreciate you as a customer and hope that you will
enjoy years of use from your plasma cutter.
Congratulations on your purchase.
The new, redesigned LOTOS LT P 7500CNC is a non-high frequency start machine. The
“blow-back” arc start type that is used is generally safe for use in CNC applications
and is ideal for general use. Blow-back arc start type involves a rearward movement
of the electrode within the torch head when forced by the air pressure. When air
pressure is applied the movement of the electrode off its seated position against the
inner surface of the circuit grounded nozzle creates a spark, energizing the plasma
stream. With this machine’s start type and pilot arc design, you are able to cut on any
metal surface without having to contact to strike an arc which is ideal for cutting items
like expanded metal or uneven surfaces. This Cutting machine has a wide range of
uses which is suitable for cutting: stainless steel, alloy steel, mild steel, copper and
other color metal materials.
There are several other key features on the LT P 7500CNC plasma cutter:
➢ With the reliable “Blow-Back” non-high frequency start, the LOTOS
LT P 7500CNC plasma cutter is suitable for CNC application meaning there will be
no interference to your CNC computer system.
➢ The IPT80 torch comes with the plasma cutter features a “BLOWBACK” design
with a Euro-type Central connector. Offering improved consumable life with a
patented “BACK STRIKING” design.
➢ Latest IGBT Inverter Technology
➢ 2T/4T Function enabled.
➢ Post-flow control provides the time of the post flow air so consumable life is
increased and the torch can be cooled for an extended period of time, if desired.
➢ Built-In Air Regulator with preset air pressure
➢ The pre-installed NPT 1/4” industry type D plug and air filter regulator allows you
to quickly connect to your air compressor by using the existing coupler on your air
compressor.

7
❖ WHAT’S INCLUDED
✓ Power Supply:
✓ Cutting Torch with
Central Connector:
✓ Ground Clamp &
Cable:
✓ Consumables:

8
❖ POWER SUPPLY RATINGS
LTP7500CNC
Specification
220V±15%
Inverter Type
IGBT
Maximum Rated Output
75 A
Start Type
Blow-Back Type
Torch Type
IPT80 Non HF Plasma Torch
Duty Cycle @ Rated Amps/Volts (40° C) 1
(Output V/A)
60% @ 75 A100%
100%@ 50 A
No load voltage (V)
284 V
Voltage Input (U1)
Standard 220/ 240 V (+-15%)
50/60Hz 1 Phase
Maximum Inrush Amps (I1MAX)
70 A
Maximum Rated Effective Amps (I1EFF)
48.5 A
CNC Port
YES
Air Post Flow Timer
Adjustable
Minimum Air Compressor Requirement
4.5 CFM @ 80 psi/ 30-60 Gallon reserve
Duty Cycle/ Over Current Protection
Yes
Minimum Operating Air Pressure
(Safety Cut-Out Threshold)
35 psi
Recommended Operating Air Pressure
(Set with Air Flow set to “Constant Flow”)
40-70 psi
Maximum Supplied Air Pressure
(From Compressor/Tank)
75 psi
Ideal Cut Thickness (Hand Torch)
1’’ ( 20mm )
Max Severance Cut @ 3 IPM (Steel)
1.25’’ ( 30mm )
Minimum Water Ingress Protection Standard
IP21S
Efficiency
>90%
Cooling Method
Full Time High Velocity Fan with Tunnel Design
Dimensions (approximate)
620 x 375 x 400mm
Weight (Bare Unit)
36 lbs.
1 Duty Cycle is percentage of 10 minutes that unit can weld at rated load without overheating.

Front & Rear Panel Layout
9

Torch protection indicator, It illuminates when the consumable parts of the
1 machine are not well installed or the torch head is shorted. Meanwhile the
Machine stops working.
2 Power indicator, It illuminates when the machine is powered on
And it glitters after arc is successfully ignited.
Warning Overheating indicator, It illuminates when the working temperature of the
3 IGBT is overly high. Meanwhile, The machine stop working.
Air-check indicator, it illuminates
when the machine is under air
check status. At this moment, the
machine can not cut/
2T indicator torch switch when
the machine is under 2T status.
Explosive view of machine:
10
4T indicator torch switch when
the machine is under 4T status.
5
Normal cutting mode, the machine
can cut when this indicator
illuminates.
4

CNC connection:
ARC VOLTAGE OUTPUT:
Pin 1+ / 2-, Ratio 1:1
This is signal of arc voltage, 1:1 output for CNC
system torch high or low movement
SIGNAL CONTROL:
Pin 1 / 2 for ON signal control input.
This is torch switch control torch ON/OFF
Pin 3 / 4 for successful arc starting signal output
for CNC system right or left movement.
Quick Setup
11
1. Connect the IPT80 Plasma torch to the machine. Insert the torch
connection into the torch connection receptacle at the front of the
machine and screw up hand tight. Caution: Do not to bend the pins
located insde the torch connector.
2. Connect the ground clamp to the output terminal of the machine and
tighten.
3. Connect the air
supply to the air
connection located at
the rear of the machine.
Turn on the air supply.
4. connect the machine to
the correct power supply
and switch on the
machine using the on/off
Switch located at
the rear of the machine.
5. select 2T or 4T
torch control
6. Set the amperage dial
Set the air pressure at
60-70PSI

Consumable Installation
12

13
INSTALLATION
PLEASE READ ENTIRE INSTALLATION SECTION BEFORE STARTING INSTALLATION. BE
SURE THAT ONLY QUALIFIED PERSONNEL PERFORM THIS INSTALLATION.
❖ MACHINE SETUP
ELECTRIC SHOCK can be fatal
 Have a qualified electrician install and service this equipment.
 Turn the input power OFF and unplug the machine from the
receptacle before working on this equipment.
 Allow machine to sit for 5 minutes minimum to allow the power capacitors to
discharge before working inside this equipment.
 Do not touch electrically hot parts.
 Machine must be plugged into a receptacle that is grounded according to the National
Electrical Code and local codes.
 Do not remove or defeat the purpose of the power cord ground pin.
➢ SELECT SUITABLE LOCATION:
The machine will operate in harsh environments. Even so, it is important that
standard measures are followed in order to assure the machine is long-lasting and
reliable in operation.
 The machine must be located where there is open space such that the air
circulation in the back and out the front will not be restricted.
 Avoid getting dirt and dust in the machine. Failure to observe these precautions
can result in excessive operating temperatures, and the machine will shut down
by itself.
➢ ENVIRONMENTAL AREA:
Keep the machine dry. Do not place it on wet ground or in puddles. Avoid rain water.
Operating in rain is not allowed.
➢ INPUT CABLE CONNECTION (enclose installing diagram):
 Every machine has an included power cable which must be connected
to coordinated voltage class in compliance and according to input voltage of cutting
machine. We recommend connecting this machine to 75A circuit breaker under
220/240V. If cutting machine power voltage is 220/240V and is connected
wrong to AC 380V, it may cause internal components to burn up.
 Make sure power cable is connected to power switch reliably and prevent from
oxidizing.
 Make sure power voltage is inside the waved range.

14
➢ OUTPUT CABLE CONNECTION:
 Make sure copper screw at end of torch is connected to gas-electrical integration
terminal, then tighten them clockwise (prevent from leaking gas).
 Connect the ground cable to the positive terminal in front panel, then tighten it.
Note: The receptacle is keyed. Align the key on the work lead connector with the opening
at the top of the receptacle on the power supply.
Push the work lead connector all the way into the receptacle on the power supply and
turn clockwise, approximately 1/4 turn, until the connector is fully seated against the stop
in order to achieve an optimal electrical connection.
Caution: Ensure the work lead is fully seated in the receptacle
to prevent overheating.
➢ CHECK:
 Check if cutting machine is grounded reliably and according to standard.
 Check if all connectors are connected firmly.
 Check if power voltage is correct.
➢ NOTE THE FOLLOWING:
 Ensure that the work clamp and the work piece make good metal-to-metal
contact. Remove rust, dirt, paint, coatings and other debris to ensure the power
supply makes proper contact with the work piece.
 For the best cut quality, attach the work clamp as close as possible to the area
being cut.
 Do not attach the work clamp to the portion of the work piece which will be cut
away.

15
OPERATION
PLEASE READ AND UNDERSTAND THIS ENTIRE SECITON BEFORE
OPERATING YOUR MACHINE. ONLY QUALIFIED PERSONNEL SHOULD
OPERATE THIS EQUIPMENT. OBSERVE ALL SAFETY INFORMATION
THROUGHOUT THIS MANUAL.
❖ SAFETY OPERATIONS
ELECTRIC SHOCK can be fatal
 Have an electrician install and service this machine and its equipment.
 Turn the input power off at the fuse box, disconnect or unplug supply lines, and
allow machine to sit for a minimum of five minutes to allow the power
capacitors to discharge before working inside this machine.
 Do not touch electrically “hot” parts. Turn the input power OFF and unplug the machine from
the receptacle before working on this equipment.
FUMES AND GASES can be dangerous
 Keep your head out of fumes.
 Use ventilation or exhaust to remove fumes from breathing zone.
WELDING SPARKS can cause fires or explosions
 Keep flammable material away.
 Do not weld, cut, or gouge on containers that have held or are currently holding
combustibles.
ARC RAYS can burn
 Wear eye, ear and body protection.

16
❖ OPERATION STEPS
 Turn on the system: Set the ON/OFF switch to the ON (I) position. Screen will turn on and
will show the current volume after 5 Seconds.
 Set the 2T/4T model switch
2T/4T Locks the torch in the ON (fire) position.
 With the 4T option selected, press the trigger to fire the torch. You can then
release the trigger while continuing to cut. Press the trigger again to stop the
arc. The arc also stops if you lose transfer.
 With the 2T option selected, press the trigger to fire the torch. You need to
hold the trigger while continuing to cut. Release the trigger to stop the arc.
 Adjust the air flow
Set the mode switch to Air Check mode.
 Adjust your air compressor’s output air flow and pressure and make it is
adequate to machine, open the valve of your air compressor.
 Adjust the Pressure-Reducing Valve and set the input PSI for your
cutting.
 Set the output AMPs
 Turn the adjustment knob to change the amperage. Make sure cutting
current is adequate to machine specifications according to thickness of
cutting piece.
 Keep a distance of 0.06Inch(1.5mm) * from cutting nozzle to the work piece,
press the trigger of the torch and burn/strike arc, sparks of arc striking will
diminish immediately. User can begin to cut.
*Please use the Stand Off Guide mounted to PT60 torch to keep the distance

17
❖ Operating the I PT 8 0 Torch with Stand Off Guide
The standoff guide is placed on the cutting surface. This maintains an
optimal 1/8" standoff distance between the plasma cutting tip and the work, this
is especially suitable if your hands are unsteady, or if you wish to use a straight
edge guide or pattern guide. It also helps extend consumables’ life.
1. Wear your safety gear. Generally, you want the same type of protective gear when Weld-
ing and cutting, plasma has high arc voltage if the job or bench is wet and you place
your hand or arm on it you can become part of the circuit and
receive a shock. Be sure you are wearing insulated shoes and
gloves, full length pants and covered shoes, wear eyes
protection(a #5 shade is the minimum eyes protection) with
other shade required depending on amperage a face shield is
also recommended.
2. Connect the earth clamp securely to the work piece or the work bench.
3. place and hold the torch vertical at the edge of the plate.
4. Pull the trigger to energize the pilot arc. The cutting arc will start when the nozzle is
moved closer to the edge of the work piece. When the cutting arc has cut through the
edge of the plate, start moving evenly in the direction you wish to cut.
5. Correct amperage and travel speed are important and relevant to material thickness and
are correct when sparks are exiting from the work piece. If sparks are spraying up from
the work piece, there is insufficient amps selected or the travel speed is too fast.
6. To finish cutting, release the torch switch. The air flow will continue for 20 seconds to
cool the torch head.