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
ZENA™ mobile welding system
Power Generator Testing/Cleaning
for All ZENA™ Mobile Welders Utilizing Factory Installed
ZENA™ Series 150, 200, or 250 Power Generators

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 2005, 2007, 2008 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.
Protected by US Pat. 6,512,119. Other US & Foreign Patents Pending

Table of Contents
ZENA™ Power Generator Testing (all models)...........................................................................................................................................1
Belt Drive ............................................................................................................................................1
Electrical Function ................................................................................................................................1
ZENA™ Power Generator Care & Maintenance ......................................................................................................................................3
A. Lubrication .....................................................................................................................................3
B. Wet Conditions ...............................................................................................................................3
C. Cleaning......................................................................................................................................... 3
D. DO NOT… ....................................................................................................................................4
Cleaning Slip Rings/Brushes......................................................................................................................................................................................5
Step 1 – Inspection Cleaning PRIOR to Removal from Drive Motor ............................................................ 5
Step 2 -- Disassembly ............................................................................................................................5
Step Three – Slip Ring Cleaning .............................................................................................................6
Step Four – Reassembly.........................................................................................................................7
Return for Service.............................................................................................................................................................................................................8

1
ZENA™ Power Generator Testing (all models)
Belt Drive
Proper belt drive efficiency is key to insuring long term trouble free generator operation.
This is achieved by having three things in balance -- drive pulley size, drive pulley belt
wrap, and proper belt tension. Not too loose and definitely not too tight. If things are in
balance, belt tension will be correct and the belt will not slip.
A quick method of checking belt tension and slip is to span the generator pulley with the
thumb and forefinger of both hands. Then try to turn the generator in the direction of its
normal rotation for V-belt drive, and in the opposite direction for serpentine/flat belt drive
installations, using as much rotational force as you can exert by hand while carefully
observing belt tension on each side of the generator pulley. Unless you are VERY strong,
you should not be able to get the belt to slip. And, just as important, you should see/feel a
slight amount of slack in the belt on one side of the pulley.
Static test belt tension can also be tested (a bit more accurately) by using a properly sized
socket wrench on the power generator’s pulley bolt to try to rotate the power generator in the
direction of its normal rotation for V-belt drive installations, and in the opposite direction for
serpentine/flat belt drive installations. The pulley should be quite difficult to turn using
moderate hand pressure. Often an engine will "turn over" before any belt slip will be noted.
At the same time, you should notice a very slight slackening of the belt tension on one side
of the pulley. If any slippage is noted, the point of failure should be easy to determine.
Belt tightness should be rechecked after the first few of hours of operation.
Electrical Function
You can easily check for a component failure in the Power Generator by following the
following procedure.
Disconnect the two wires which are used to connect the Control Module or Voltage
Regulator to the Power Generator’s control (1/4” spade) terminals, and check in the
electrical resistance between either of the terminals and the case of the Power Generator.
A normal reading is an “open” circuit (an infinite resistance).
If your meter shows any measurable resistance, in either test, your Power Generator has
either a brush assembly, or rotor assembly failure, and should be returned for repair1.
If your meter shows no measurable resistance, check the electrical resistance between the
two Power Generator control (1/4” spade) terminals with an ohm meter. A normal reading
is between 1.8 and 2.4 ohms2. If your meter shows a resistance of less than 1.8 ohms, your
Power Generator may have a rotor failure (or the remote possibly that there is a piece of
foreign matter bridging the brushes), and should be returned for repair3.
If the electrical resistance measured between the control terminals is higher than the
“normal” range of 1.4 to 2.4 ohms4(for example, 10 ohms, or 20 ohms, or more) it is
1If desired, this component is field replaceable by a competent technician (or skilled owner).
2A reading of as much as 3-5 ohms may be “normal” – a result of a brush being slightly out of position when the
generator is not rotating. Spin the generator and retest if this sort of reading occurs.
3If desired, this component is field replaceable by a competent technician (or skilled owner).
4A reading of as much as 3-5 ohms may be “normal” – a result of a brush being slightly out of position when the
generator is not rotating. Spin the generator and retest if this sort of reading occurs.

2
typically an indication that grease, or some similar material may have caused “fouling” or
glazing of the brushes and/or internal slip-rings. Cleaning can be accomplished in the field,
if necessary5, but is best done under factory (dust free) conditions.
Disconnect the generator’s output terminal from any load, and check in the electrical
resistance between each of the terminals and the case of the Power Generator.
A normal reading is an “open” circuit (an infinite resistance).
If your meter shows any measurable resistance, from either terminal to the case, your
Power Generator has a possible defect in its output power insulation system, and the
generator should be returned to the factory for repair 6.
If the foregoing resistance readings are correct, a test of the output voltage of the generator
under full field / full speed operating conditions should be made.
If you are using the generator in a welding application, this is done by starting the welder
(pressing the power button or other on/off control in use) and rotating the power control to
maximum (fully CW).
If you are using the generator in a charging/generating application, this is done by
temporarily (and briefly) connecting one of the two control terminals to ground, and the
other to a source of DC voltage between 12 to 14.5VDC while the generator is being rotated
at a speed of between 6,000 to 7,000 rpm -- with both of the generator’s output terminals
disconnected from any loads (particularly a battery)7.
A normal DC voltage reading between the positive and negative terminals of the generator,
under these conditions, is between 70-80 volts. A reading substantially lower than this (say,
50-55 volts), indicates a possible failure in the generator’s rectifier or stator assemblies, and
the generator should be returned to the factory for repair8.
5See enclosed instructions.
6This sort of problem can be repaired in the field, by removing a foreign object, or moving a component which is
touching the case interior, or replacing one of two sub assemblies. Additional trouble analysis, and some
disassembly, may be required to determine which component to replace.
7Use insulated 1/4” spade terminals or insulated clip leads for your connections to prevent an inadvertent short
circuit during testing.
8If desired, this component is field replaceable by a competent technician (or skilled owner).

3
ZENA™ Power Generator Care &Maintenance
The ZENA power generator is very robust. Other than keeping it 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 performance and for maximum service life.
Keeping your 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 soapy water followed by a fresh water rinse
(DO NOT use water or strong detergent cleaning solutions from a pressure washer).
After rinsing, excess water should be removed 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.
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 drive engine briefly to allow the
cooling fan to remove most excess moisture from inside the case.
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 component may be cleaned
with any aerosol cleaner/ degreaser designed for electronic components, OR the
outside surfaces can be cleaned with a clean cloth moistened with mineral spirits or
kerosene.
The interior of the generator can be cleaned with a light application of any aerosol
cleaner/degreaser designed specifically for electronic components9, AND/OR with a
mixture of dish washing detergent (or some other mild detergent10 which is effective at
removing/cleaning grease/oil).
After cleaning, the generator should be rinsed with fresh water. Excess water should then
be removed by operating the generator’s drive engine briefly with sufficient speed to drive
9CAREFULLY read the product instructions and warnings BEFORE using any sort of aerosol based cleaner to
insure that the cleaner is COMPLERELY safe for use with electronic components, AND/OR electrical varnishes,
AND/OR all types of plastics or resins.
10 NOT detergents which are used for cleaning auto parts or which are, in any way, reactive with aluminum, or
other metals

4
the generator to its normal operating speed to allow the cooling fan to remove most excess
moisture from inside the case. If available, compressed air can be used to good advantage
at this time to assist in the process of “drying” the generator.
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 internal
components by simply hanging the Control Handle so that its electrode holder points
“down”. Moisture trapped in the handle or its components will drain out or evaporate.
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.

5
Cleaning Slip Rings/Brushes
Cleaning can be accomplished in the field, if necessary -- but is best done under factory (dust free)
conditions. Factory cleaning will be performed free of any labor charge, with charges only for return
freight cost.
However, if circumstances dictate that you need to clean the unit yourself, carefully follow these
instructions:
Step 1 – Inspection Cleaning PRIOR to Removal from Drive Motor
If slip ring/brush cleaning is needed because of oil or chemical contamination, before
removing the generator from its drive motor/engine, or beginning disassembly of the
generator, inspect the power generator for residual amounts of antifreeze, grease, hydraulic
fluids, or oil on the outside of the generator or on visible internal components.
If contamination of the exterior is noted, the exterior of the generator may be cleaned with
any aerosol cleaner/degreaser designed specifically for electronic components11,
AND/OR with a clean cloth moistened with a solvent such as mineral spirits or kerosene,
AND/OR with a mixture of dish washing detergent (or some other mild detergent12 which is
effective at removing/cleaning grease/oil).
The interior of the generator can be cleaned with a light application of any aerosol
cleaner/degreaser designed specifically for electronic components13, AND/OR with a
mixture of dish washing detergent (or some other mild detergent14 which is effective at
removing/cleaning grease/oil).
After cleaning, the generator should be rinsed with fresh water. Excess water should then
be removed by operating the generator’s drive engine briefly with sufficient speed to drive
the generator to its normal operating speed to allow the cooling fan to remove most excess
moisture from inside the case. If available, compressed air can be used to good advantage
at this time to assist in the process of “drying” the generator.
Step 2 -- Disassembly
Place the generator on a clean, dust free workbench -- resting on its side.
Identify/locate the four Allen head cap bolts that hold the generator case parts together.
11 CAREFULLY read the product instructions and warnings BEFORE using any sort of aerosol based cleaner to
insure that the cleaner is COMPLETELY safe for use with electronic components, AND/OR electrical
varnishes, AND/OR all types of plastics or resins. If ANY doubt as to suitability of a chemical exists – DO
NOT USE IT.
12 DO NOT USE detergents which are used for cleaning auto parts or which are, in any way, reactive with
aluminum, or other metals.
13 CAREFULLY read the product instructions and warnings BEFORE using any sort of aerosol based cleaner to
insure that the cleaner is COMPLETELY safe for use with electronic components, AND/OR electrical
varnishes, AND/OR all types of plastics or resins. If ANY doubt as to suitability of a chemical exists – DO
NOT USE IT.
14 DO NOT USE detergents which are used for cleaning auto parts or which are, in any way, reactive with
aluminum, or other metals.

6
Then, using a properly sized, unworn, Allen wrench, loosen first one pair of opposing bolts –
then the second pair. When all four bolts have all been loosened, remove all four bolts from
the case15 and set them aside.
Locate the point where the front case and the iron lamination of the stator assembly meet.
With a small screwdriver, working around the case perimeter, gently pry the front case
assembly away from the stator assembly. At this point, you should gently pull the two
sections of the generator apart while taking care to support the considerable weight of the
rotor section which is normally supported by the needle bearing located in the rear case
assembly.
At this point, the rotor shaft end will likely have a bit of bearing grease on it. Wipe off this
grease and place the front case/rotor assembly onto your workbench.
As the rotor assembly is removed, the brushes will spring free of the brush guide. The
brushes must be returned to their guides, and be held in place. until reassembly of the
generator is complete.
For the model SR150 and SR250 series generators, the brushes can usually be pushed back
into place by hand (or by gentile manipulation with a pair of needle nosed pliers) and then
held in place by a straightened paper clip threaded through the holes provided in the brush
assembly, brushes16, and the rear generator case.
For the model SR200 series generators, the brush assembly must be removed from the rear
case in order to reposition, and secure, the brushes for reassembly of the generator.
Removal is simple, requiring only a 1/4” nut driver to remove the two #8 hex head machine
screws which hold the brush assembly in place. With the brush assembly outside of the
case, the brushes can be easily pushed back into place, by hand, and then held in place by a
straightened paper clip. As the brush assembly is reinstalled, the wire is threaded through
the holes provided in the rear generator case.
Step Three – Slip Ring Cleaning
The copper slip rings can usually be cleaned by simply by rubbing briskly with a rough cloth
soaked in denatured alcohol. Cleaning can also be accomplished by very carefully using a
strip of a very fine grade wet or dry polishing sandpaper - greater than 1200 grit. Though
this method presents some risk that the contour of the slip rings might be altered – possibly
affecting future performance and brush service life.
However, much better, safer, and quicker results can be obtained by using a common, and
popular, household metal polish designed for cleaning/polishing brass and copper – sold in
the USA under the trade name Brasso®. This compound will make quick work of the job,
leaving the copper slip rings bright and shinny with little chance of changing the contour of
the slip rings. Once clean, the slip rings should be wiped off with a cloth soaked in
denatured alcohol to remove any polish residue which might impair future performance.
At this time, the brushes should also be wiped off with the alcohol soaked cloth to remove
any greasy reside which may reside on the brush surface.
15 When removing SR200 series generator case bolts, take care to not loose the four stainless 3/8” nuts which are
used as spacers between the two sections of the rear housing assembly.
16 When brushes are new, holes in the brushes facilitate the use of a brush retaining wire. After some time in use
the, portion of the brushes with holes for the retaining wire will be worn away. At this point the brushes are not
worn out or unserviceable, only about a third of their useful service live has been expended.

7
Step Four – Reassembly
Place the rear generator case on the bench top – orienting the generator case so that the
rotor assembly can be gently lowered into the case until the end of the rotor shaft enters the
rear needle bearing.
At this time take particular care that the output terminals are positioned, in relation to the
generator mounting foot and tensioning tab so as to meet the needs of your particular
installation.
Once in place the generator should be placed on its side.
At this point, gently press together the two case halves insuring proper fit of the stator
assembly’s iron laminations into the front case assembly. NOTE the two parts may not be
in full contact at this point – however, the case parts will be pulled into position as the case
bolts are inserted and tightened.
Insert the four case bolts removed previously making sure, if reassembling a model SR200
series generator, not to forget to position the generator’s four stainless steel 3/8” spacer nuts.
Loosely firm up all four bolts then continue to tighten an opposing pair to a moderate degree
of tension. Then do the same with the other opposing pair.
Now, moving around the generator, moving from one adjacent bolt to another, tighten the
bolts bit by bit until all are fully secure.
As a final step, remove the wire segment holding the brushes away from the slip rings. On
the SR150 and SR250 series generators this wire extends from inside the case near the rear
bearing support. On SR200 series units you will likely need a pair of needle nosed pliers to
grip the wire and pull it free of the rear case.
This completes the reassembly process.
Your generator may now be retested, and if found satisfactory, returned to service.

8
Return for Service
If you determine that you have a problem which requires either further troubleshooting
assistance from our tech support department or need a return authorization for a possibly
malfunctioning component for test/repair call 877-ZENA INC (toll free in the USA) or 615-
897-2011, e-mail us at [email protected],or you can FAX us at 615-897-2023.
If, for any reason, you cannot reach us by phone, it is permissible to return the suspect
component for repair without a formal authorization. Just make sure that you include a
written description of the problem that you have found as well as a legible return address
(and a telephone #, if available, that we can uses if it is necessary to contact you).
IF YOU DO HAVE TO RETURN AN ITEM, insure it and make sure that it is packed
carefully and properly (use our packaging materials if at all possible).
• DO NOT USE foam “peanuts” for padding (dust from these can get into your welding
equipment and cause future problems) or any other type of Styrofoam packaging
materials that can crumble when broken/torn/stressed.
• MAKE SURE that at least 2” of firm padding material (paper/cardboard, bubble-wrap,
or non crumbling foam (like the foam pads that we use in our packaging) is placed on
all sides of any item so that the item is FIRMLY held safely in the center of the
package -- DO NOT SCRIMP ON PADDING.
• USE A GOOD quality box with STRONG side walls.
Careful attention to packaging will avoid extra charges for shipping damages.