E-2

THEORY OF OPERATION

E-2

 

 

 

 

TOC

TOC

 

 

 

 

 

GENERAL DESCRIPTION

 

 

Section

Master

 

 

 

 

The NA-5 is a fully automatic wire feed

voltage on digital meters. These preset

 

 

 

 

 

 

 

 

control unit. It is designed for multiple

conditions are internally monitored and

 

to

to

 

process CV operation and can be used

remain constant until changed by the

 

 

with a variety of wire feeder heads, con-

operator.

 

Return

Return

 

 

 

tact nozzles and welding processes.

 

 

 

 

 

 

 

 

 

 

The NA-5 control unit enables the oper-

 

 

 

 

 

ator to preset wire feed speed and arc

 

 

 

 

 

FIGURE E.1 Input Circuits

 

 

 

 

CONTACTOR CLOSURE (#2 AND #4)

TACH FEEDBACK (MOTOR RPM)

 

 

 

 

 

 

ARC VOLTS (SET & ACTUAL)

 

 

 

REMOTE VOLTAGE CONTROL (A, B, C)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WORK SENSING (#21)

 

 

 

 

 

 

1/2 AMP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

F501

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TOC

 

 

 

 

115VAC

 

 

 

 

 

 

 

 

 

 

SET VOLTAGE

 

 

 

TOC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ODE

SENSING (#67)

VOLTAGE

 

 

 

 

 

 

 

 

 

 

 

 

 

R

 

 

 

 

BOARD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

T

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TACH

C

 

 

 

 

 

TRAVEL

 

 

 

 

 

 

Section

Master

 

 

 

 

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L

 

D

 

 

 

 

 

RECEPTACLE

FLUX

 

 

 

 

 

 

 

 

 

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C

 

 

 

 

 

 

 

 

RECEPTACLE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MOTOR

 

S

 

 

 

A

 

3

 

 

 

 

 

 

 

 

 

 

U

 

 

 

R

A

CR

 

 

 

 

 

 

 

 

 

 

 

 

 

C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P

 

 

 

 

N

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P

 

 

 

V D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

O

 

2

 

 

 

 

 

 

to

to

 

 

 

 

 

 

 

 

L

 

 

 

L

S

 

 

 

 

 

 

 

 

 

A

 

 

 

 

Y

START

STOP

INCH

T

H

CR

 

 

 

 

 

 

 

 

 

V

 

V

 

 

A

U

 

 

 

 

 

 

 

 

 

 

R

F

 

V

SWITCH

 

DOWN

G T

 

 

 

 

 

 

 

Return

Return

 

 

 

M

O

O

 

SWITCH SWITCH

E

D

 

 

 

 

 

 

 

 

 

 

A

L

I

L

 

O

 

 

 

 

O

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

W

 

 

 

 

 

 

 

 

 

T

T

E

T

 

L

 

 

 

 

N

CR

 

 

 

 

 

 

 

 

 

U

A

L

A

 

T

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R

G

D

G

 

A

 

 

 

 

 

 

P

 

VOLTS

SPEED

OPTIONAL

 

 

 

 

E

E

 

E

 

G

 

 

 

 

 

 

 

START

 

 

 

 

 

 

 

 

 

 

 

 

 

 

START

INPUT

 

 

 

 

P

 

 

E

 

 

 

 

 

DC SUPPLY VOLTAGE

R

 

 

 

BOARD

TIMER

CIRCUIT

 

 

 

 

 

 

 

 

 

 

 

 

 

STRIKE

 

 

 

 

POWER

 

 

 

 

 

 

 

 

 

 

 

 

O B

 

 

 

 

SWITCH

BREAKER

 

R1(2 OHMS)

 

O F2

 

 

 

 

LOGIC

 

STRIKE/WELD PROCEDURE

 

 

OPTIONAL

CRATER

 

 

#31

 

 

 

 

W

 

 

 

 

 

 

 

C

O

 

 

CRATER

TIMER

 

CONTROL

 

 

 

 

 

 

 

 

 

 

ENABLE

 

 

BOARD

 

 

 

 

 

 

 

 

 

 

BOARD

 

 

 

 

 

CABLE

115

 

 

 

 

E

 

 

 

 

 

 

E A

 

 

 

 

 

RECEPTACLE

V A C

 

 

 

 

R

 

 

 

 

 

 

 

 

 

D

R

 

 

OPTIONAL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WELD

 

 

 

#32

 

 

F1

B

 

 

 

 

 

 

 

 

 

U D

WELD

TIMER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R

 

 

 

 

 

 

 

 

 

 

O

FIELD

DIRECTION

SIGNAL

 

F

 

 

 

E

 

 

 

BURNBACK

 

 

 

 

 

 

 

 

A

 

 

 

 

 

VOLTS

SPEED

TIMER

 

 

 

 

 

 

 

 

 

 

 

 

 

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R

 

 

 

 

 

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D

 

 

MOTOR

ARMATURE

E

 

 

WELD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

G

N

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A

A

 

CURRENT

 

 

 

 

 

 

 

 

 

 

T1

T2

 

 

 

 

 

 

REED SWITCH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

T

B

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E

L

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

S

E

 

 

 

 

 

 

 

 

 

TOC

TOC

 

 

 

 

 

 

 

 

 

 

I

 

 

 

 

 

 

 

 

 

 

 

 

 

115VAC

 

 

 

 

 

 

G

S

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

N

I

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

A

G

 

 

SET SPEED

 

 

 

 

 

 

 

 

36VAC (18+18VAC)

 

 

 

 

L

N

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

S

A

 

 

 

 

 

 

 

 

 

 

V

 

 

 

 

 

 

 

 

 

L

 

 

 

 

 

 

 

 

 

Section

Master

 

 

22VAC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C

 

 

 

 

 

 

 

 

 

 

 

 

10VDC REFERENCEVOLTAGE

 

 

 

 

 

 

 

 

 

 

 

 

 

DC VOLTAGE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VOLT

SPEED

WIRE FEED SPEED (SET & ACTUAL)

 

 

 

CONTROL

 

 

 

TACH FEEDBACK (MOTOR RPM)

 

METER

METER

 

 

 

 

 

 

 

 

BOARD

 

 

 

 

 

 

 

 

to

to

 

BOARD

BOARD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INCH

 

 

 

 

 

 

 

 

 

 

 

 

Return

Return

 

 

 

 

 

 

 

 

UP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SWITCH

 

 

 

 

 

 

 

 

 

 

 

 

 

DIGITAL

DIGITAL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

METER

METER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INPUT POWER CIRCUITS

 

 

The NA-5 control unit is supplied with

motor.

The voltage board receives

 

 

115VAC power usually from the welding

115VAC and transforms and rectifies it

 

 

power source. The 115VAC power is

to 24VDC for the "work touch sensing"

 

 

connected to the control box circuitry

circuit.

The T1 and T2 transformer pri-

 

 

through the control cable receptacle,

maries are also supplied with 115VAC

TOC

TOC

the input power switch and a 5 amp cir-

via the F1 (1/2amp) fuse on the power

cuit breaker.

board. The T1 and T2 secondary wind-

 

 

Section

Master

 

ings offer a variety of isolated AC sup-

The 115VAC is applied through a 2 ohm

ply voltages to the power, logic and

 

 

 

 

resistor to the power board where is

meter boards.

to

to

rectified and controlled to supply arma-

 

 

ture and field voltage to the wire drive

 

 

Return

Return

 

 

NOTE: Unshaded areas of block logic diagrams are the subject of discussion.

 

 

 

 

NA-5

 

 

Page 49
Image 49
Lincoln Electric NA-5NF, NA-5SF service manual General Description, Input Power Circuits

NA-5S, NA-5N, NA-5SF, NA-5NF specifications

The Lincoln Electric NA-5NF, NA-5SF, NA-5N, and NA-5S are advanced welding helmets that are pivotal in enhancing the safety and efficiency of welders in various applications. These models are designed to provide exceptional protection and visibility, making them indispensable tools in the welding industry.

One of the main features of the NA-5 series is the auto-darkening filter technology. This feature allows the helmet to automatically adjust its shade based on the intensity of the arc. As the welder strikes an arc, the lens darkens instantaneously, shielding the eyes from harmful rays generated during the welding process. This functionality not only ensures safety but also enhances productivity, as welders do not need to manually flip the helmet up and down.

The helmets are equipped with a wide viewing area that allows for better visibility and precision while working. With a large lens, welders can easily monitor their work and surrounding environment, minimizing the risk of accidents. Additionally, the lightweight design of the NA-5NF, NA-5SF, NA-5N, and NA-5S provides comfort during extended periods of use, reducing neck strain and fatigue.

The NA-5 series is also well-regarded for its durability. Constructed from impact-resistant materials, these helmets can withstand the rigors of demanding work environments. This durability extends the lifespan of the helmet, making it a cost-effective investment for both professional and hobbyist welders.

Another notable characteristic is the adjustable sensitivity and delay settings found in certain models. These settings allow the user to customize the helmet based on their specific welding conditions. For instance, a welder can increase sensitivity for low-amperage tasks or adjust the delay to allow for a smoother transition from dark to light after completing a weld.

Furthermore, the helmets come with a reliable battery life, ensuring that they can be used for long periods without interruption. Some models also feature solar assist functionality, which helps recharge the auto-darkening filter, enhancing their overall efficiency.

In summary, the Lincoln Electric NA-5NF, NA-5SF, NA-5N, and NA-5S welding helmets represent a significant advancement in personal protective equipment for welders. Their combination of auto-darkening technology, wide viewing area, lightweight design, durability, and customizable settings makes them an excellent choice for anyone engaged in welding tasks. With these helmets, users can achieve greater safety and efficiency in their work, enabling them to focus on their craft with peace of mind.