Motor Controllers - FAQs

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When trying to pick out a controller for my application, I see the desired model has some missing numbers. For example: 1204-2XX. What does the “XX” stand for?
The “XX” is a designation number that tells us what options are configured on a certain controller. Some of these options could be certain error detection configurations, software differences, or even an exclusive controller for a certain customer. We have some internal documentation which helps us figure out which controller would best fit your needs.
I have a motor controller that failed. It is a 1244-4401. I have an extra one on my shelf, but the model states it is a 1244-4403. It looks exactly the same as the old one. Will this work?
This is a tough question to answer just by looking at the model number of the controller without any supporting information. More than likely this will NOT be a “drop-in” replacement. Usually there is enough of a difference in the controllers, even though not externally apparent, that you will have some type of error occur. You will need to contact a Curtis representative and they will be able to research this and find out if it is possible to replace one controller with another.
I would like to have a manual for the Curtis controller I have. Where can I obtain this?
Most Curtis manuals can be found on our web page. The link is the following:
My controller has a problem and I need to fix it. I have an electrical background and would like to fix it myself. Can I have the schematics for this controller along with any replacement components I would need to fix it?
Unfortunately Curtis cannot provide this type of information and product. The schematics for our products are proprietary and cannot be distributed outside of Curtis. This also applies to the components that are found inside our products. Our authorized partner, Flight Systems Industrial Products (FSIP), does offer a repair service on selected controllers for a fee. You need to contact FSIP at 717-254-3747 and ask for the Repair Department.
I have a Curtis controller that failed. Where do I return this to receive a credit?
If you obtained this product through an official Curtis distributor, this should be returned back to the place of purchase. If you purchased this directly from Curtis, there are two locations in Curtis that handle product returns. If it were a motor controller, controller accessory, or a throttle, you would need to contact our California office at (925) 961-1088. Any other Curtis product would need to be handled through the New York office. Their number is (914) 666-2971.
Is it possible to have my controller customized to fit our needs?
This depends on many different factors. First we need to know the extent of customization. Next we need to know your projected volumes you plan on purchasing. After this information is obtained, it will be brought to project management’s attention and a decision will be made if it feasible. We will then contact you with applicable fees. An off-the-shelf- item is certainly more desirable to sell and would have a higher likelihood of inventory than a custom unit.
Can I obtain the internal controller components so I can fix it myself?
Due to liability and many other considerations, Curtis will not support external repair of our products. Repairs need to be performed at our authorized repair partner, Flight Systems Industrial Products (FSIP) at 717-254-3747.
What do I need to do to my controller to make my vehicle go faster?
This depends on what type of controller you have. It is advisable to keep the controller on the factory settings. Adjusting the current/voltage settings of the controller may result in vehicle component damage.
There are so many different controllers to choose from. Where do I start?
First you need to gather information about your application (motor type, motor current/voltage specifications, throttle type, type of application, and other components in your system that may interact with the controller). Once all of this information is gathered, you can call the Curtis Instruments Applications Engineering department at (914) 666-2971 for further advise.
How long in advance do I need to place an order for a controller?
Most of our products are “made-to-order”, which means we do not make the product until the order is placed. Our lead times vary due to the manufacturing location so please call the Curtis Customer Service team at (914) 666-2971 for exact lead times.
My controller states two voltages on its label. Does this mean it works within that range or only for the two voltages?
The controller works on any voltage within that nominal range.
Do Curtis Controllers have regenerative (regen) braking?
Permanent Magnet, SepEx and AC controllers do. The series wound models utilize Plug braking and Neutral braking (auto-plug). This slows the vehicle when changing direction or selecting neutral drive, but does not put energy back into the battery. For slow maneuvering operations it is very effective.
My controller has neutral braking, but sometimes it just coasts. Why?
Neutral braking (auto-plug) monitors the current flowing into the motor so that when the motor stops (near zero current) the direction contactors are released. If you have a poor floor surface contaminated with oil or grease and the braking force is set too high on the controller, then the tire will skid and the motor current will be zero which then turns off the contactors and the vehicle coasts. Floor conditions are important for safe operation of material handling equipment.
The neutral braking on my vehicle is too harsh even when set to a minimum level. What can I do?
Certain motor and gearbox configurations can cause this condition. It is possible to fit an Albright armature field weakening contactor that reduces the braking force when neutral is selected. Contact your local Curtis office for assistance.
What is the advantage of using a microprocessor based controller?
The microprocessor based controllers allow the OEM to adjust many control parameters using a 1311 programmer, so that superior vehicle performance can be achieved. In addition to this the microprocessor based model record any intermittent fault or operator errors which can be recovered by a service engineer also using the 1311 programmer. This greatly reduces any downtime due to fast vehicle analysis and speedy rectification.
Besides the motor controller what other products do I need for my EV?
You will need connectors for the battery leads and controller, throttle unit, contactors, battery discharge indicator, battery charger all of which Curtis can supply. For many OEM’s we even build all of this into one kit with one part number, making life easier for you the customer.
What size of heat-sink do I require?
This is difficult to answer as many conditions effect the heat generation and transfer process. The controllers are rated for 2 minutes at full current based on the conditions specified in the relevant manual. Aluminum plate of 6-10mm is often used. Start with the largest area possible and run tests to ensure the maximum operating temperature of the controller 85oC is not exceeded. Thermal transfer compound and electric fans may be used if the controller is used in a confined space or worked very hard.
Can I connect two controllers in parallel to get more power?
No, the controllers regulate the power using a Pulse Width Modulation (PWM) technique. The power that flows from the controller is in the form of a square wave. It is not possible to synchronize the square wave PWM from two controllers. Contact your local office for high power controllers.
Can one controller drive more than motor?
In most cases yes. The controller can either be switched to a different motor via contactors if the motors are used at different times or two motors may be connected in series or parallel. AC induction motors cannot be connected in parallel or series and separate controllers should be used. The controls can be connected in parallel or via CANbus.
Are the controllers UL approved?
Yes, Curtis controllers are approved and the Underwriters Laboratory file is UL?????
Are the controllers CE marked?
No, Curtis controllers are not CE marked as they are not a self contained system. EMC susceptibility and emissions are highly variable depending on the exact layout of connecting wires and motor types. It would therefore be incorrect to CE mark a controller and assume that the complete operational system would meet CE requirements. Curtis does however ensure that the controller not only meets but exceeds the CE requirements on an approved vehicle simulator.
Is there an on-charge interlock available to prevent the vehicle being driven away while on charge?
This is really only applicable to vehicles that have an on-board charger. Our Permanent magnet controllers have an inhibit connection that connects to on-board chargers such as the Curtis 1600 series and disables the controller while a mains input is present. With AC controllers this function can be enabled using the Vehicle Control Language (VCL). For other controllers either a relay interface or a 1310 vehicle system controller may be used.
What types of vehicle use Curtis Controllers?
Anything with battery supplies in the 12-144V range. The list is practically endless but here are a few; Mining locomotives, counterbalance trucks, Arial platforms, golf carts, mobility scooters, electric dragsters, municipal road vehicles, aircraft tow tractors, helicopter movers, stacker trucks, floor sweepers, pipe inspection vehicles, pedestrian tugs, cargo handlers, bicycles, neighborhood electric vehicles, compactors, pallet trucks, fairground rides, river boats……