Zena 150 series User manual

I N C O R P O R A T E D
330 Club Springs Road
Elmwood, TN 38560
Phone: [phone]
Fax: [phone]
www.zena.net
Operator’s Manual
for all
ZENA™ Backpak™ welders
Equipped with WC.12 Welding Control Module,
SC101 Active Speed Control Module
&
Series WSC Welding Cables/System Controls
or
PCIM Power Control Interface with
TS101 Electrode Contact Sensor/Switch Module

This document contains the latest information available at the time of preparation. Every effort has
been made to ensure accuracy. However, ZENA, Incorporated takes no responsibility for errors or
consequential damages caused by reliance on the information contained herein.
ZENA, Incorporated reserves the right to make product enhancements and/or modifications at any
time without prior notice.
Copyright 2004-2005 by ZENA, Incorporated.
All rights reserved. No part of this publication may be reproduced in any form or by any means
without the prior written permission of the publisher.
ZENA, Incorporated
330 Club Springs Road
Elmwood, Tennessee 38560
Printed in U.S.A.
ZENA™is a trademark owned by ZENA, Inc. for its welding systems and related products.
ZENA™is a trademark owned by ZENA, Inc. for its farm tools and equipment.
Backpak™is a trademark owned by ZENA, Inc. for its farm tools and equipment.
Protected by US Pat. 6,512,119. Other US & Foreign Patents Pending

Table of Contents
I. Introduction ...........................................................................................................................................................................................................1
II. IMPORTANT SAFETY WARNINGS & REFERENCES....................................................................................................3
A . Danger of Personal Injury .................................................................................................................3
B. Danger of Electrical Shock............................................................................................................... 3
C. Fire & Explosion ............................................................................................................................. 3
D . Safety / Operating References...........................................................................................................3
E. Other Safety Publications/References: ...............................................................................................4
III. Checking Your Package Contents .........................................................................................................................................................5
IV. ZENA Welder Specifications.....................................................................................................................................................................7
V. Operator Controls -- Basic “Stick”/Arc Welder Configuration ..........................................................................................8
VI. Using your ZENA™mobile welding system................................................................................................................................10
A. Cabling Attachment....................................................................................................................... 10
B. System Operation –– All Models..................................................................................................... 10
VII. Care & Maintenance....................................................................................................................................................................................12
A. Lubrication ................................................................................................................................... 12
B. Wet Conditions ............................................................................................................................. 12
C. Cleaning....................................................................................................................................... 12
D. DO NOT… .................................................................................................................................. 13
VIII. Trouble/Fault Diagnosis.............................................................................................................................................................................14
A. System Control Modules -- Internal Diagnostics ................................................................................ 14
B. Welding Power Problems ............................................................................................................... 15
C. Optional Power Control Interface Module (PCIM) ............................................................................. 28
C. Mechanical Problems..................................................................................................................... 28
IX. If You Need Help/Support........................................................................................................................................................................30
A. The Internet -- www.zena.net ......................................................................................................... 30
B. E-Mail -- [e-mail] ............................................................................................................ 30
C. Fax -- 615-897-2023 ....................................................................................................................... 30
D. Mail............................................................................................................................................. 30
E. Telephone Support......................................................................................................................... 30
ZENA, I ncorporated Limited Warranty..........................................................................................................................................................32

ZENA mobile welding system -- Operators Manual -- Series 150 & 200 Welders
11
I. Introduction
Congratulations, you have purchased the finest portable DC arc welder in the world! And, possibly
the lightest!
You will find it to be one of the most versatile and useful tools that you own. Designed to meets the
needs of professional welders, working farmers, and industrial maintenance personnel, it is well suited
to a wide range of other uses -- industrial maintenance and fabrication, marine
maintenance and fabrication, construction, nursery work, estate maintenance, arts &
crafts, residential repairs, ornamental iron work, airborne maintenance activities, and
more.
In fact, given its ultra compact design and extraordinarily light weight, in addition to
redefining the terms “mobile” and “portable”, as they apply to welding equipment -- it
is creating new areas of utility -- vastly increasing the number and types of jobs that
welding equipment can address in the field!
Your new welding system has a number of unique features which, when compared to
conventional welders, make it safer and easier to use and superior in welding
performance. Read this manual carefully, and thoroughly familiarize yourself with all
controls, design features, safety features, and specifications before you begin to use it.
And, don’t neglect to also focus on the engine and its specific operating/maintenance
instructions -- included both here in this manual and in the Operators Manual provided
by the engine manufacturer. Attention to this, will insure that you will be able to safely,
and to properly use your new welder.
The ZENA system produces a high frequency pulsating DC current for welding which
provides a number of benefits over conventional DC welders. For example:
!Improved welding “feel” -- easier to start and maintain an arc1
!Electrically “stirred” weld bead provides additional penetration, less impurities,
and easy to remove flux deposits -- producing ultra-smooth and clean welds
even when used by inexperienced operator.
!Arc length is much less critical than past technology. Maintain an arc even with
electrode tip in puddle!
!Use any welding rod (AC or DC), including aluminum, stainless , iron, nickel.
!Weld with long cables (up to 200 ft.) without noticeable loss of power
!Deeper than normal weld penetration for a given power setting
While it is available with conventional controls best suited to rental and ultra harsh duty
condition, most Backpak welders are shipped with the unique control system for which
ZENA welders are renowned -- one which is designed to greatly enhance user safety
and to provide the operator unprecedented control of the welding process. With this
control system:
!Welding power is not present at the electrode tip unless a safety/control button is
depressed and held down. Change rods without any danger of shock (even when
standing on a wet surface) and remove excess flux from rod/electrode tips
without danger of inadvertent arcing
1Other arc welders require you to maintain an arc length equal to the diameter of your welding rod for optimum
results. With ZENA welders, you can produce excellent welds with arc lengths ranging from .1 to 2 times rod
diameter. For a 1/8” rod, you can hold your rod tip in direct contact with the puddle or as far away as 1/4” and
still produce a good weld.

ZENA mobile welding system -- Operators Manual -- Series 150 & 200 Welders
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!Welding power is infinitely variable while welding -- no performance limiting pre-set power
settings
!Welding power is controlled from the welding handle and can be varied while welding to insure
good weld penetration even when welding materials of varying thickness and structural stability
!Special controls assist with arc starting by allowing the operator to briefly use high power while
starting an arc and then dropping back to a preset power setting when arc condition is
satisfactory
!The Backpak welder also features a highly sophisticated electronics speed controls system
which has been designed to insure optimum engine efficiency from the welder’s powerful 2-
cycle engine when welding and when idling at rest
Additionally, your welder includes features which you would expect to find on any high quality
welder:
!Output power is fully isolated from engine, or earth ground.
!Weld with both standard and reverse polarity.
However, even our “standard” welding controls are unique -- with power to the welding electrode and
engine speed control automatically activated whenever the welders electrode tip makes suitable
electrical contact with a metal object to which the welders “ground” clamp has been securely
connected. Simply breaking the welding arc will simultaneously shut off welding current and set the
engine back to idle.

ZENA mobile welding system -- Operators Manual -- Series 150 & 200 Welders
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II. IMPORTANT SAFETY WARNINGS &REFERENCES
A. Danger of Personal Injury
Serious injury or death may result if your welding equipment is not properly installed, used,
and maintained.
Welding is an inherently dangerous activity, and ALL welding equipment can be very
dangerous if used improperly. Welding is often performed in dangerous environments such
as high places, around water, in close quarters, etc., and it is critically important that the
operator be aware of the dangers associated with these conditions. Operators must be
aware of these dangers, trained in safe operating practices, and properly supervised and/or
assisted.
The ZENA welding system incorporates within its design safety features and special
controls that enhance operator safety. These features and controls should never be
disabled.
Welding equipment, including the ZENA mobile welding system, should only be used by an
experienced welder using proper eye protection devices equipped with a #12 to #14 shade
filter lens and proper protective clothing. If used improperly or carelessly severe eye
damage and/or severe burns can occur.
Welding equipment can damage and/or interfere with the operation of delicate electronic
equipment. Use of the ZENA welding system (or other welding equipment) should not be
attempted by individuals who use pace-makers and/or other life-sustaining electronic
medical implants and/or devices.
B. Danger of Electrical Shock
When properly installed, the ZENA system converts your vehicle into a fully functional
mobile welder capable of producing very high direct current (DC) welding energy
(depending on the model, from 150 to over 800 amps). As such, it should be always be used
with extreme caution. In some cases, even though the system, when operating, produces
low voltage DC, life threatening electrical shock is possible.
C. Fire &Explosion
When welding out of doors, particular attention should be given to the prevention of fires.
Sources of combustion are the welding arc, flame, flying sparks, hot slag, hot metal, and
other heated materials.
Do not attempt to weld in remote areas without a suitable fire extinguisher and/or sufficient
water and tools to extinguish any inadvertent fires which may be caused by the welding
process.
Do not weld or cut containers which have held combustible materials. Arcing against
compressed gas cylinders can cause explosion or damage to cylinder rendering it unsafe.
Do not weld near any source of oxygen.
D. Safety /Operating References
This manual is a critical safety device. It incorporates, within its text, information that is
critical to operator safety and to safe equipment operation. We recommend that it be kept
with the equipment at all times. Should it become damaged and/or otherwise unusable,
replacement copies will be provided at no charge. Call 877 ZENA INC or 615-897-2011 to

ZENA mobile welding system -- Operators Manual -- Series 150 & 200 Welders
44
order replacements. You can also order replacements via mail from the address noted on
the cover, or via e-mail ([email protected]).
E. Other Safety Publications/References:
US Govt. Printing Office, Washington, DC 20402 -- Code of Federal Regulations (OSHA) --
Section 29 Part 1910.95, 132, 133, 134, 139, 251, 252, 253, 254, and 1000.
American National Standards Institute, 1430 Broadway, NY, NY 10018 -- ANSI Z49.1
“Safety in Welding and Cutting”; ANSI Z87.1 “Practice for Occupational and Educational
Eye and Face Protection”; ANSI Z88.2 “Standard Practice for Respiratory Protection”
American Welding Society, 550 NW Lejeune Road, POB 351040, Miami, FL 33135 --
AWS C5.3 “Recommended Practices for Air Carbon Arc Gouging and Cutting”; AWS
F4.1 “Recommended Safe Practices for Welding and Cutting Containers”
National Fire Protection Association, Battery Park, Quincy, MA 02269 -- NFPA 51B “Fire
Prevention in Cutting and Welding Processes”
Canadian Standards Association, 178 Rexdale Bl., Rexdale, Ontario, Canada M9W 1R3 --
CSA Std. W117.2. “Safety in Welding, Cutting and Allied Processes”

ZENA mobile welding system -- Operators Manual -- Series 150 & 200 Welders
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III. Checking Your Package Contents
Unless you have ordered an extra long welding cable/system control handle assembly (or a special
MIG or TIG interface/adapter kit), your ZENA welding system (and any accessories which you have
ordered) will typically be packaged in a single container designed to protect the product from the
normal hazards of domestic and/or international shipping. It consists of an outer carton that contains
the welding cables/system controls and any small accessories which you may have ordered, and an
inner carton that contains the power generating unit and its electronic control module2.
Except as otherwise noted on an enclosed packing list/invoice, a typical package should contain:
Qty. Item Description
1 ea.
1 ea.
1 ea.
1 ea.
1 ea.
MW150 or MW150T Backpak welder
Welder Operators Manual & Limited
Warranty
Engine Manual & Limited Warranty
Electrode Holder/Control Handle & Cable
Assembly3
Ground Clamp & Cable Assembly
1 ea. Invoice/Packing List
2In some cases, the Welding Power Control Module may be shipped in the outer carton.
3And/or, whatever optional control interface accessory which you may have purchased with your welder.

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IV. ZENA Welder Specifications
Power Output @
100% Duty Cycle
150 amps.
Typical Voltage Output
@ Full Power
w/Arc Established
20-24VDC w/High
Frequency Waveform
Modulation
(Typically 700 modulation transitions per
second)
Typical Voltage Output
@ Full Power
w/NO Arc Established
58-78VDC w/High
Frequency Waveform
Modulation
(Typically 700 modulation transitions per
second)
Min. Power Generator
Shaft Speed for
Maximum Output
Power
approximately
6,500 RPM
(Higher shaft speeds – up to 15,000 rpm -
have no detrimental effect on welding
performance, but welding at these speeds
requires larger drive pulley diameters)
DC Power Required
(When Welding)
11-14.5 volts @
7 amps. maximum
(1 to 4 amps at average welding power
settings)
DC Power Required
(When NOT Welding)
None
Control Circuit
Protection
Internal Fuses (2) (2 amp. & 10 amp.)
Welding Controls Internal, Solid State (Built into electrode holder/welding cable
assembly)
Accessory Controls Internal (2)
SR150.12 welding power generator with WC12 control module

ZENA mobile welding system -- Operators Manual -- Series 150 & 200 Welders
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V. Operator Controls -- Basic “Stick”/Arc Welder Configuration
The ZENA welding system features a unique, but very simple, control system.
All welding controls, except for welding polarity selection (determined when connecting welding
cables to the Power Generator), are built into the welding electrode holder4.
Multi-position Electrode/Welding Rod Clamp
By selecting the proper groove in the clamp’s contact area welding rod position can be set to a
number of convenient positions relative to the control handle (i.e., 0˚, 45˚, 90˚, 135˚).
The clamp is opened by depressing the insulated
arm attached to the clamp.
Power Button
Turns welding power ON when the Power Button
is pressed and held down. Welding power is not
present at the tip unless the Power Button is
depressed and held down.
Power Control Dial
The Power Control Dial allows you to precisely
control welding current/power. Welding power is
infinitely variable and can be adjusted at any time
– even while welding.
Turning the control fully counter clock-wise
yields minimum power and turning it fully CW
sets the unit to produce maximum welding power.
This control can assist an experienced welder in
insuring excellent weld penetration even when
welding materials of varying thickness and
structural stability.
Boost Button
This control is provided to assist you with arc
starting in difficult conditions (i.e., working with
thin gauge, or rusty, or painted metal) by allowing
you to briefly select high power to start an arc and
then dropping back to your preset power setting when arc condition is satisfactory.
Press and hold the Boost Button for full power output, release the Boot Button to return instantly to
the power setting selected by the Power Control Dial.
NOTE: The Boost Button must be held down in addition to the Power Button.
4Welders purchased with optional controls for MIG and/or TIG welding -- or, with our PCIM (Power Control
Interface Module) will differ from the description above. However, the same control features are incorporated into
these alternate controls.
Boost
Button
Multi-position
Welding Rod
Clamp
Power
Control
Dial
Power
Button

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Welding Polarity
Welding polarity is selected/determined by the attachment of the
welding cables, using the supplied wing nuts, to the terminals at
the rear of the Power Generator Unit.
Red cable lug to Red terminal &
Black cable lug to Black terminal
=reverse (positive electrode) welding polarity
Red cable lug to Black terminal &
Black cable lug to Red terminal
=standard (negative electrode) welding polarity

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VI. Using your ZENA™mobile welding system
The ZENA system is exceptionally easy to use. However, the preparation of the equipment for
use varies in some small degree depending on the model and control interface that you are
using, the method of installation used to attach the welder to your engine or vehicle -- and,
whether or not your are using one of our cable extension accessories.
A. Cabling Attachment
1. Model BPW150 and BPW150T welders
a) Attach the welding cables to wing-nut terminals at the rear of the Welding
Power Generator selecting standard (negative electrode) or reverse (positive
electrode) welding polarity depending on your welding needs (reverse welding
polarity is the usual choice for most steel alloys and aluminum -- Red to Red /
Black to Black).
b) Attach the black control cable connector to the black mating connector attached
to the short gray cable coming out of the Control Module which is affixed to the
outside of Welding Power Generator.
2. Model BPW150 and BPW150T welders equipped with BJ150.4 Quick Disconnect Kit
a) Plug the Gray Plastic connector which has been installed on your welding
cables into the mating Gray Plastic connector located at the rear/bottom of your
backpack frame.
b) Attach the black control cable connector to the black mating connector attached
to the short gray cable coming out of the Control Module which is affixed to the
outside of Welding Power Generator.
c) Use the cable wing-nut terminals at the rear of the Welding Power Generator to
select your desired welding polarity -- selecting standard (negative electrode),
or reverse (positive electrode), welding polarity depending on your welding
needs (reverse welding polarity is the usual choice for most steel alloys and
aluminum -- Red to Red / Black to Black).
B. System Operation –– All Models
1) Start the engine.
2) Engine speed will automatically rise to welding speed when you press the power button
on your electrode holder -- returning to idle when you release the power button to stop
welding5.
3) Starting from the welder’s minimum power setting (Power Control Dial fully
counterclockwise) set the Power Control Dial to an approximate power setting for the
size of welding rod used. See the chart below:
Series 150
30-40% CW 60-75% CW 90-100% CW
5When welding stops the engine will, typically, accelerate to a speed beyond the normal
welding speed before returning to idle. This is normal -- the result of delaying throttle
reduction until the welding arc is broken and the instantaneous reduction in engine load
that occurs when the arc is broken.

ZENA mobile welding system -- Operators Manual -- Series 150 & 200 Welders
1111
3/32 inch 1/8 inch 5/32 inch
As soon as you start welding, the Power Control Dial setting should be adjusted to yield
the desired arc and proper weld penetration for the type of welding rod which is being
used, the environmental conditions, and the type of material being welded. Remember,
you can adjust the power at any time while you are welding.
4) Depress the Power Button, strike an arc, and begin welding. Remember, if you are
having trouble striking an arc, for any reason, you can simultaneously depress the
Power Button and the Boost Button to produce an extra strong arc. Then, as soon as an
acceptable arc is established, release the Boost Button by sliding your finger off the
Boost Button and moving it fully onto the Power Button to return to the welding power
determined by the Power Control Dial’s setting. Remember, you can adjust the power
while you are welding, and you can also use the Boost Button at any time while welding
in situations where extra power for a short time is desired.

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VII. Care &Maintenance
The ZENA mobile welding system is very robust. Other than keeping components clean, NO regular
preventive maintenance is required.
A. Lubrication
Not required. All moving parts are permanently lubricated.
B. Wet Conditions
All critical electrical parts are sealed from moisture and all mechanical components are
designed to operate in wet conditions (but not when immersed in water).
C. Cleaning
Proper cooling is necessary for optimum welding performance and for maximum service
life. Keeping your welding system’s components clean is most important.
1) Dust/Dirt Removal
Compressed air is best for removing accumulations of dust and/or dirt from the interior
and exterior surfaces of your Welding Power Generator. If compressed air is not
available, clean by rinsing with a stream of fresh water (DO NOT use water or cleaning
solutions from a pressure washer). After rinsing, excess water should be removed by
operating the engine briefly to allow the cooling fan to remove most excess moisture
from inside the case.
2) Removing Corrosive Chemicals/Salts
If your welder is operated around salt water or used in conditions where its components
may be exposed to corrosive chemicals, solvents, degreasers, antifreeze, and/or liquids
with a high mineral content, it should be rinsed off with fresh water as soon as possible
after exposure. Remove excess rinse water from the Welding Power Generator by
using compressed air (if available), or by operating the engine briefly to allow the
cooling fan to remove most excess moisture from inside the case. Excess water can be
removed from the Control Handle by simply hanging it so that the electrode holder points
“down”. Any moisture trapped in the handle or its components will then drain out or
evaporate.
3) Removing Grease and Oils
If grease, hydraulic fluids, oils or other petroleum based lubricants cause dirt to
accumulate on the outside of system components, the unit may be cleaned with any
aerosol cleaner/ degreaser designed for electronic components, OR the unit can be
cleaned with a clean cloth moistened with mineral spirits or kerosene and rinsed with
fresh water.
4) After Operating in Wet Conditions
Excess water should be removed from the Welding Power Generator by operating the
vehicle’s engine briefly to allow the cooling fan to remove most excess moisture from
inside the case. Excess water can be removed from the Control Handle’s components
by simply hanging the Control Handle so that its electrode holder points “down”. Any
moisture trapped in the handle or its components will drain out or evaporate.

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D. DO NOT…
!use spray lubricants of any sort on any component; or
!operate the unit in very dusty and or dirty conditions without insuring that cooling air
reaching the unit is as dust and/or contaminant free as possible; or
!allow antifreeze compounds to contact system components without cleaning the
affected component with fresh water; or
!allow accumulations of grease and/or dirt to form on system components; or
!apply any sort of paint to any system component; or
!clean system components with aerosol brake cleaners, carburetor cleaners, spray
degreasers, or other chemicals except as noted above in “Cleaning” above.

ZENA mobile welding system -- Operators Manual -- Series 150 & 200 Welders
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VIII. Trouble/Fault Diagnosis
Your ZENA Backpak welder has been designed to be very simple to use. In addition, no expense has
been spared to insure that it is also an extremely reliable and long lasting product.
However, should you have any problems with your system, the information below will help you to use
built-in fault diagnosis tools to isolate and (often) to solve the problem that you are having.
A. System Control Modules -- Internal Diagnostics
Both engine and welding controls are housed in compact weather tight modules which
include diagnostic circuits which can be used to help troubleshoot your welder. The
modules which are most typically used with the ZENA Backpak welder are illustrated
below. Each of the diagrams show the module with the cover removed to expose the
diagnostic indicators used with each module.
1. Welding Power Control Models Model WC.12B -- Location of Internal Indicators and Fuses
By removing 4
screws, the cover
of the Welding
Power Control
Module can be
removed.
With the cover
removed, you will
see the objects
shown in the
drawing to the
right. The four
indicators which
are labeled Lamp
#1 through Lamp
Fuse (10 amp)
Fuse (2 amp)
Lamp #3
(control logic
function)
Lamp #2
(control output function)
Lamp #1
(power)
Lamp #4
(speed cont.
function)
#4 will be used in the fault diagnosis steps that follow.
2. Automatic Engine Speed Control Module Model SCM.V2 -- Location of Internal Indicators
and Fuses
By removing 4
screws, the cover
of the Speed
Control Module
can be removed.
With the cover
removed, you will
see the objects
shown in the
drawing to the
right. The six
indicators which
are labeled Lamp
Fuse (2 amp)
Lamp #5
(logic function/
at/above welding speed)
Lamps #2 - 4
(speed control function /
tachometer readout)
Lamp #6
(tach. signal in)
Lamp #1
(speed cont.
function)
#1 through Lamp #6 will be used in the fault diagnosis steps that follow.