The NSS Pony 20 SCA is the largest Pedestrian Carpet Extractor produced by National Super Service. It has a large 20-gallon tank that allows the unit to clean large carpeted areas quickly and efficiently. Overall, this is one of the best carpet extractors produced for the cleaning industry. Although this machine is extremely reliable and durable, over time parts can break and may need to be repaired. The Pony 20 SCA is a simple machine with only five major components that can fail. These components are the gear drive motor, vacuum motor, brush motor, pump, and solenoid valve. It is quite simple to diagnose these parts and quickly repair them. When replacing parts on the NSS Pony 20 SCA, it is important to use National Super Service OEM parts to ensure the machine will function properly after repair.
The Pony 20 SCA is a self-propelled, variable speed unit that can cover large areas quickly. The drive system for this unit is powered by a 120 volt geared motor that drives the wheel assembly. The drive motor is connected to the wheel assembly by a chain, if the drive system fails and the machine does not move there are four components that could be damaged. The first and largest of these components is the gear motor itself, this can be tested by running direct power to the motor to see if it turns on. The second component is the speed control board which increases or decreases the amount of voltage going to the motor depending on how fast the machine needs to run. There is a dead man’s switch on the lever assembly that turns the brush motor on and off. Over time, switch components can wear out and fail and may need to be replaced. The last component to fail is the circuit breaker, which over time can wear out and overload prematurely. The circuit breaker is a three amp, 120 volt unit that, when overloaded, closes the circuit to the brush motor. The other reason this switch will turn off is if the brush motor draws more than 3 amps this may be due to bad bearings in the drive wheel or something caught around the wheel preventing it from going forward or backward.
The Pony 20 SCA recovers solution from carpet using an internal vacuum motor that draws water through the vacuum shoe at the rear of the unit into the recovery tank. If you experience loss of suction, it is important to check that all seals and gaskets are clean and in working order. One of the main reasons for loss of suction is a damaged dome gasket located on top of the machine. Any holes or cracks in this dome gasket will cause vacuum leaks and you will experience a loss of suction. Before looking at the vacuum motor as the culprit, also check the vacuum shoe and vacuum hose at the rear of the machine for obstructions that could cause decreased suction. There are two main components within the vacuum system. These two components are the vacuum switch and the vacuum motor. To find which component has failed, use a multimeter to check if you are getting 120 volts at the vacuum motor when the switch is on. If you get 120 volts at the vacuum motor, the vacuum motor has failed prematurely. Other ways to tell if the vacuum motor is failing is to listen for a loud high pitched grinding noise or a grinding noise that would come from the motor bearings. Water can sometimes enter the vacuum motor from the recovery tank if the machine is not emptied before the water level reaches the float valve. Other ways that water can enter the vacuum motor is from excess suds in the recovery tank of carpet cleaning detergents. One way to deter foaming is to use an antifoam agent by adding it to the recovery tank before use. If you don’t get 120 volts at the vacuum motor when you turn the switch on, the vacuum switch has probably failed and needs to be replaced. When replacing the vacuum motor on the Pony 20 SCA, it is also important to replace the vacuum motor gasket to ensure a tight seal for optimal performance.
The next component that could fail is the brush motor. The Pony 20 SCA’s brush motor drives a rotating filament brush that is used to agitate the fibers of the carpet. This increases debris collection and is optimal for food service areas and places where dirt and grime collect on the carpet. The number one reason the brush motor will fail on this unit is if debris gets caught around the brush or if the rotating brush bearings go bad. This will place an excessive load on the engine and it will wear out prematurely. Another component to check if the brush is not turning is the brush belt, this belt could be slipping on the pulley or it could be cut. If the brush is not turning, the three components that could be bad are the brush switch, brush switch, or brush motor. To diagnose these parts, take a multimeter and check the voltage coming from the brush switch to the switch when the switch is on. If you get voltage at the brush switch, continue to the next step. Next check the voltage coming from the brush switch to the brush motor, if there is no voltage there then the brush motor has probably failed. If you are not getting voltage from the brush switch to the brush switch, replace the pump switch with an OEM NSS switch. If you are not getting voltage from the brush switch to the motor and you are not getting voltage from the pump switch to the brush switch, your brush switch has probably failed and needs to be replaced. There is also an AC rectifier in the system that converts AC power to DC for the brush motor. If the brush switch, brush switch, and brush motor are receiving power, the rectifier probably needs to be replaced.
The next internal system that could fail is the pumping system. The pump system sprays a cleaning solution onto the carpet. If no solution is coming out of your machine, the first thing to check is the jets at the bottom end of the unit. There are five jets on the Pony 20 SCA, these jets are quick connect jets that, when twisted, detach from the jet housing. It is not necessary to unscrew the Jets from the spray bar. If you need to replace the old jet housings, be sure not to over-tighten the jets as this will break the plastic on the spray bar. To clean the jets, soak them in a descaling solution and then use compressed air to clean the jet nozzles. If the Jets are clean and you don’t get any solution on your carpet, there are three components that could have failed. These components include the pump switch, pump or solenoid. To test which component has failed, use a multimeter to check the voltage between the pump switch and the pump solenoid. If you are not reading any system voltage, it is likely that the pump switch has failed and needs to be replaced. If you get voltage from the pump-to-pump switch, one of the two components could be bad. The pump and solenoid are attached, but the solenoid can be removed from the pump. In this unit, the pump will run continuously when the pump switch is activated. The solenoid will open and close to allow water to pass through the pump and then through the spray bar and jets onto the carpet. If you are getting power to the solenoid and pump and you don’t hear the pump running continuously, the pump will need to be replaced. If you are getting power to the pump and the pump is running, then the solenoid will need to be replaced.
In general, the National Super Service Pony 20 SCA is easy to maintain and repair. There are other mechanical components that may need to be replaced, but this article covers the main components that make the machine work. It is important not to touch live wires when diagnosing the machine. For optimum performance and reliability, use only National Super Service parts when servicing this unit. NSS parts can be purchased from a local dealer or online store. Our certified service technicians can help you find the right part for your floor equipment.
