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Frequently Asked Questions

General Information

What are your business hours?

We are available 24 hours per day, 7 days a week to provide sales or services to keep your business running. Our regular business hours are Monday through Friday, 8:00 am to 4:30 pm. Our after-hours “Emergency” phone number is 314-638-0166.

Do you have Rate Sheets for your services?

Absolutely! We don’t list them online as our Rate Sheets are always changing with our expanding service options and promotions. But we’re happy to share it with anyone whom asks, simply call us at 314.638.9641, reach out directly to the appropriate department contact, or submit a request online.

Crane & Hoist

Are yearly load tests required on a hoist and crane?

There is no specific time period during which load tests must be performed once the initial installation is inspected and load tested. Some states require operators to load test hoists and cranes every four years, but, in most cases, if the hoist is not altered, repaired or modified, it can remain in service indefinitely without a load test being required.

Can rated loads for hoists and trolleys be different from the crane’s rated load?

The short answer to your question is “yes.” However, ASME B30.16 stipulates that when a system is comprised of components with different rated capacities, the rated load of the “system” shall be based on the lowest-rated individual component.

System is defined as the combination of Monorail, Hoist and Trolley in the case of a Monorail and CraneHoist and Trolley in the case of an Underhung Crane.

ASME B30.16-1.3.2 states that the supporting structure, including trolleys, monorail, or crane, shall be designed to withstand the loads and forces imposed by the hoist for the rated load.

Do monorails need to be labeled with their rated load?

According to ASME B30.11, rated load markings are not required on monorails but are recommended. Before marking the monorail, a qualified person must determine the rated load on the monorail beam. Once the monorail is marked, the rating should be legible from the ground floor. ASME’s recommendation also applies to marking the rated loads of hoists on the monorail. For more information on hoist marking guidelines, see ASME B30.16.

What is the anti-collision device on overhead cranes?

It mainly includes laser type, ultrasonic type, infrared type, electromagnetic type, all use the principle that light or radio wave travels, reflects and the distance can be measured. When two overhead cranes travels to pointed position, the overhead crane mechanism rings alarm bell and gives the stop command at the same time.

How should an overhead crane be left when not in use?

1) Keep Load Close to the Ground

If the crane will be left with a load attached to it, the load should always be lowered as close to the ground as possible. Keeping tension on the cable will ensure it doesn’t swing or risk coming removed when it shouldn’t. Keeping the load high up in the air, however, invites problems with an accidental drop or other related issue.

2) Never Leave the Crane Powered On

The crane should never be left without an operator with the power left on. This would allow someone to come begin using the crane without proper training or authorization. In addition, when the crane is on it will typically be using the electric motor to maintain the cranes position. When the crane is turned off, it can use the hoist brakes, which is safer and also won’t put as much stress on the machine. This will also help to minimize the amount of electricity used, which will save the facility money.

What are the OSHA crane & hoist standards? Can you help me adhere to them?

Our Crane and Hoist division has certified technicians to provide monthly, quarterly or annual inspections. We will tag all of the equipment inspected and give a written report on each piece, with a quotation for repairing or replacing any unsafe equipment.

Motor Service & Repair

What is considered a good Meg rating?

The recommended minimum insulation resistance to ground when measured at, or corrected to, 40 degrees C, is the rated machine voltage potential in kilovolts +1, in megohms. Unit should be meggered 1 – 10 minutes for a polarization index value. 2.0 is considered a minimum value when you divide the 10 minute reading by the 1 minute reading. The PI value is the result of that division.

Can you rewind a 3 phase motor for single phase?

Yes, but it is usually not cost-efficient.

Can you change bearings in the field?

It is possible to change bearings in the field depending on the motor, the location of the motor, and its environment.

How much does it cost to rewind a motor?

The cost to rewind a motor can vary greatly based on the HP, voltage, speed, and frame size. An estimate can be provided with this information but a physical evaluation of the motor will allow us to provide the most accurate repair cost.

What is your turnaround time on Rewind of motor?

The turn-around-time would depend on the hp of the motor, any parts needed, additional machine work, when will we get the motor and customer willingness to pay for available, and needed Overtime. We can turn around an expedited motor rewind in as fast as 3 days assuming we have the parts we need.

How much time(?) to balance a fan?

It would depend on the size of the fan, onsite or in shop and how far out of balance it is. Most fans can be balanced in a 2-3 hours.

Can you test a winding in the field for faults?

Yes, we have portable meggers, surge testers, and DC absorption equipment that can be used in the field.

Automation & Electrical

Can you help me get a used production line I bought up & running?

Yes, our automation and controls division can evaluate what your needs are and will customize a design, fabricate the enclosures and controls and program the system to your needs. We will then provide CAD drawings for future reference.

Can you find deterioration or weakness in motor mounts & motor support structure that may be causing detrimental vibration?

Yes, Zeller Technologies has an advanced camera specifically made for motion analysis. Enabling us to record in order to analyze and find issues like this. Our certified technician can perform this service and then literally show you his findings in the consultation that would follow. 

Can you test a winding in the field for faults?

Yes, we have specific motor test equipment that will test the impedance, inductance, resistance, and phase angle, of the motor windings, performing a comparison of each to deduce if there are irregularities. This test will give us enough information in the field to know the internal health of your motor or if more extensive evaluation is necessary.

Is it necessary to laser align a belt application?

Yes, the smallest deviation from straight alignment can bring accelerated belt and sheave wear as well as premature bearing failure.

Can Zeller help me with removing a motor for repair?

Definitely. We have experience mechanics that will be able to safely unwire and pull your motor as well as supplying a truck for transport. Then, when the repair is complete we can not only install and wire but can perform the needed alignment. Zeller can provide a turnkey service on your motor repair.

Is Zeller Technologies able to help me figure out why my machine isn’t running at top speed any longer?

Without question. Zeller has the personal to determine if the issue is electrical, electronic, or mechanical. We not only find the problems but we can provide the solutions.

I know that my motor needs the bearings changed. I’d rather not pull it and send it to your shop. Can Zeller do this work in the field?

Most often yes. Depending on the horse power and the location it is usually more economical to have a Zeller technician come on site and perform this work. With specific information, Zeller can set a date to bring the necessary equipment and replacement bearings, and in most cases be in and out in one day. We will finish the job by providing the needed alignments and send documentation of the final readings.

Repair & Routine Services

Do you repair and re-certify U/L motors?

Yes, Zeller Electric entered the U/L program at its very beginning in 1977.

Do you service servo motors or spindle motors?

We service both types with limitations. The majority of the servo motors are imported. They come with many types of speed and control regulators such as encoders, TAC generators and resolvers. When we receive units that we cannot connect to our control stations to completely test, we will send them to a qualified station that can give reliable service on that particular unit.

How often should you grease bearings?

Depending on the size of the bearings, RPM, the number of hours running, if the motor is vertically or horizontally mounted, or in a hostile environment will all affect the frequency of greasing. A motor should be greased according to the manufacturer’s recommendation. A simplified chart is available that we can send you.

Is all grease compatible?

No, there are 12 different types of lubricant compounds. The chances are that they will not be compatible.

How much grease should be pumped in the bearings?

We are available 24 hours per day; 7 days a week to provide sales or services to keep your business running. Our regular business hours are Monday through Friday, 8:00 am to 4:30 pm. Our after hours “Emergency” phone number is 314-638-0166.

Do you evaluate condition of bearings and overall performance? How often should this be done? What is the cost?

Yes, we perform a service called ‘PMP’ (Predictive Maintenance Program). This service is performed with equipment running in normal state with no shutdown required. Frequency of testing depends on how critical the equipment is for plant operation. The cost of testing is based on the number of pieces and points that need to be checked. Call for a FREE ‘on site’ appraisal.

Products & Parts

What Manufacturers Do You Service/Sell?



Hoist Accessories





AC/DC Variable Speed Drive

General Accessories

Can’t Find Your Question? Connect Directly

Crane & Hoist Contact

Ryan Shelton – Manager

314.638.9641 x.229
[email protected]

Repair: Ship To

4250 Hoffmeister Ave
St. Louis, MO 63125

  • New Cranes
  • Hoist & Crane Repair
  • Control Upgrades
  • Radio Upgrades
  • Inspections
  • Load Testing
  • Tests & Maintenance
  • Certification Classes
Service Areas
  • Missouri
  • Illinois
  • Iowa
  • Indiana
  • Arkansas
  • Kansas
  • Kentucky
  • Tennessee
Larry Klevorn – Manager

314.638.9641 x.224
[email protected]

Nick Schneeberger – Assistant Manager

314.638.9641 x.230
[email protected]

Repair: Ship To

4250 Hoffmeister Ave
St. Louis, MO 63125

  • Motor repair
  • Motor rewind
  • Motor balancing
  • Equipment diagnostics
  • Pump repairs
  • Fan repairs
  • Gearbox repairs
  • So much more
Service Areas
  • Missouri
  • Illinois
  • Arkansas
  • Kansas
  • Kentucky
  • Tennessee
  • Indiana
Tom Rudloff – Manager

314.638.9641 x.259
[email protected]

Repair: Ship To

4250 Hoffmeister Ave
St. Louis, MO 63125

  • Drive & Control Repair
  • Infrared Thermography
  • Energy Efficiency & Power Analysis
  • Switchgear Testing & Upgrading
  • Panel Shop Fabrication
  • Panel Assembly Services
  • UL508a
  • AutoCAD
  • PLC Programming
  • System Integration
  • Laser Alignment
  • Balancing
  • Predictive & Preventative Maintenance
Service Areas
  • Missouri
  • Illinois
  • Arkansas
  • Kansas
  • Kentucky
  • Tennessee
  • Indiana

Our Incredible Service Promise

Keeping our customers as the priority, we back all our work, products, and parts. Transparent and forthcoming reports, and straightforward advice is what has allowed our family business to not just survive, but thrive over the past century.