Frequently Asked Questions
Explore answers to frequently asked questions about RTT’s finishing systems, equipment, installation requirements, and technical services to help you make informed operational and purchasing decisions.
Questions About Quoting and Sales
Why Sell Through Distribution?
Our distribution network allows us to provide local representation throughout North America, Canada and Mexico. Our dealers are chosen to offer expertise and services on a local basis.
Can You Help Me Select the Correct Type of Booth?
Yes, our team of experts is always available to work with our customers and distributors in the selection of the booth design and options to obtain the best possible results. From selection of the airflow design to sizing to control options, we can help.
Can I Order a Custom Booth Instead of a Standard Catalog Size?
Yes, RTT Finishing Solutions can make a booth to fit your specific needs. Just let us know what your parts are like, the building size and any other special information needed to design the right booth.
Why Is Voltage Required When Ordering a Control Panel or Air Makeup Unit?
It is important to know the correct voltage because the motor protectors in the CP and the AMU unit must be sized according to the voltage.
Does RTT Offer Complete Systems for Washing, Drying, Coating, and Curing?
Yes, RTT can provide all of the equipment needed to process your parts. We can build anything from a small batch system to a large automated coating system including multi-stage washers, ovens, booths and all of the ancillary equipment that goes with it. Just supply us with the part requirements for size, volume and quality and we can design a custom system for you.
General Questions About Products
Why Does RTT Use Nut-and-Bolt Construction for Its Spray Booths?
Nut and bolt construction provides consistent structural stability and makes for simple installation. Our booths can also be easily uninstalled and reinstalled as necessary.
What Air Volume Does the National Fire Protection Association (NFPA) Require for a Paint Booth?
NFPA requires that the booth environment has enough ventilation to maintain the concentration of flammable vapors below 25% of the Lower Flammable Level (LFL). The LFL of common solvents varies. Table G-11 in OSHA 29 CFR 1910 contains the flammable levels for common solvents.
How Does a Crossdraft Paint Booth Differ from a Downdraft Paint Booth?
The airflow direction is the most obvious difference and the name tells the story. A crossdraft moves air from one side to the other and a downdraft moves air from top to bottom. The selection depends on what is being painted. Generally speaking, parts that are longer in the vertical and short in horizontal dimension tend to fit best in a crossdraft booth while parts that have a large horizontal surface tend to fit best in a downdraft booth. The crossdraft booth limits the operator to one direction of spraying while the downdraft allows the spray operator to move around the part 180 degrees. Talk to an RTT professional to get the right type of booth for your operation.
Do I Need an Air Makeup Unit (AMU) for Every Paint Booth Installation?
All paint booths exhaust air from the building and there should be supply air to replace the air that is exhausted. It is sometimes possible to replace air with existing AMU and some installations run reasonably while pulling air through open doors, inlet fans or other means. However, the best way to supply air for a paint booth is with a suitably-sized AMU. It controls the volume of air, the velocity, and location as well as providing dirt filtration.
How Many Washer Stages Are Needed to Properly Clean My Parts?
The number of stages in a washer depends on the substrate material, the soils present on the part and the quality goals for the product. Typically, the simplest system uses three stages to clean and treat mild steel parts for products used indoors. The next step up is usually five stages for better cleaning and more corrosion protection. For outdoor products more stages may be needed. Consult with a pretreatment company or talk to one of our RTT experts to help you determine the right number of stages for your operation.
How Can I Prevent Heat From Escaping My Paint Cure Oven Openings?
Oven heat roll out is a frequent problem with process ovens. It can be aggravated by building pressure issues and oven design issues. Building air pressure is affected by the location and volume of fans (supply and exhaust) and also the opening and closing of overhead doors. Check to see if you have any sources of high or low pressure near the oven entrance or exit that could be creating air movement through the oven. If you have space, extend the vestibule of the oven so the heated zone is farther from the opening. You could add a hood and stack at the opening to capture heat roll out and get it out of the building. A properly designed oven will have features to limit heat roll out.
What is RTT's Warranty Policy?
RTT Finishing Solutions offers an exclusive Five (5) Year Warranty on all spray booths — the only manufacturer in the industry to do so. This warranty is valid when customers use our RTT high-performance RP “W-Series” exhaust filters, which are specifically designed, tested, and approved to deliver superior paint particle separation while maintaining optimal airflow in accordance with ASHRAE 52.1 standards.
Questions About Booths
How Do I Adjust the Pulse-Down Timing for My Powder Booth Cartridge Collector?
1. Turn off the power to the control panel and open the door. Wait 2 minutes for the VFD display to turn off.
2. Turn on the power to the control panel and start the fan.
3. Locate the Dwyer timer board and press the “Select” button, “Last Output” LED will illuminate, and the display will show a value.
4. Press the “Select” button, “Time Off” LED will illuminate, and the display will show a value. Use the Up/Down buttons to change the value to the desired amount of time between pulses (in seconds). Quicker pulsing will allow filters to clean faster but will require more compressed air.
5. Press the “Select” button, “Time On” LED will illuminate and the display will show a value. Use the Up/Down buttons to change the value to the desired amount of time each pulse valve will stay on (default is 100 milliseconds).
6. Press the “Select” button several times until the “Process” LED illuminates. The programming is now complete. Stop the fan, turn off the power to the control panel. Close the door and wait 2 minutes for the VFD to de-energize, then turn the power back on.
Is Incoming Gas Pressure to the Valve Train and Burner Important?
Whenever it comes to volatile gases and compounds, the gas pressure and volume are extremely important to ensure the system operates safely and properly. The incoming gas pressure to the valve train should never exceed the maximum allowable pressure of the valve train regulator. These pressures can be located on the manufacturer’s control panel door and can also be provided on the regulator by the manufacturer.
Pressures at the inlet of the valve that exceed this rating can cause damage to the regulator and internal components of the valve train. In some cases, resulting in the valve train failing to block the flow of gas even when the system is shutdown, resulting in an extremely dangerous situation of explosion and fire. The minimum gas pressure for the system is particularly important as well to ensure that there is enough gas pressure through the valve train and into the burner. Lack of gas pressure will cause issues with the BTU output of the burner and in extreme cases will cause the safety switches on the valve train that monitor low gas pressure to fault.
Typical oven pressure ranges are 2 to 5 PSI and typical Air Make-up Unit gas ranges are from 1.5 to 2.5 PSI but can change based on project designs and field requirements, check the drawings and manuals for exact ranges.
Why Are My Spray Booth Doors Being Blown Open?
• Airflow and burner output become unstable
• The system may create positive pressure inside the booth
• Doors can blow open due to improper pressure differential
Check the valve train regulator, system gas pressure, and follow the manufacturer’s recommended pressure ranges.
How Do I Adjust Airflow on My Powder Collector?
The control panel is equipped with a “Fan Speed” knob on the door. Adjust the knob to a higher value for more airflow, or a lower value for less airflow.
When Should I Change the Filters on My Spray Booth?
When it comes to determining when to change your spray booth filters, first we must differentiate between intake filters and exhaust filters. Intake filters are located where the outside or shop air is introduced to the spray booth working environment. These filters work to ensure that the air introduced into the spray booth is free from debris, which can cause defects in your coatings. Exhaust filters are in separate locations, depending on the design and construction of your spray booth. The primary function of these filters is to capture overspray from the booth working environment and prevent harmful and hazardous particulates from being exhausted into the atmosphere by the booth exhaust fans. The function of both filter types is paramount to the spray booth functioning properly and ensuring the best possible coating finish. Spray booths are designed to meet National Standards, such as OSHA and the NFPA.
When filter maintenance is neglected, the performance of the spray booth will fall below the standards’ requirements. When the spray booth performs below the designed param¬eters, proper airflow will not be present and the likelihood of overspray or dust to accumulate on the coated part increases exponentially. Because there are many different filter constructions available, it is difficult to mandate a certain time interval for filter change outs. There are many other factors that play a part in the life span of the filters, including cleanliness of the surrounding environment, type of coating being sprayed, application styles and equipment used, spray booth air speed, spray booth design and construction and design of the filters can all affect the life of the filter. However, there are some key indicators that your filters are coming to the end of their effective life span:
Intake Filters:
• When an increase in debris or dust is noticed in the booth or in the coatings.
• If you have a manometer or Magnehelic gauge to measure pressure, drop through the filter, change at the suggested loading of the manufacturer.
• Filters have been installed for six months.
Exhaust Filters:
• When overspray is noticed to be lingering in the booth more than usual.
• The spray booth fan is operating at 100% capacity.
• If you have a manometer or Magnehelic gauge to measure pressure, drop through the filter, change at the suggested loading of the manufacturer.
• Applying a coating that is capable of spontaneous combustion or other harmful compounds.
• Filters have been installed for one month.
It is best practice to establish a filter maintenance program with the help of RTT Finishing Solutions. Improper filter maintenance can affect more than just the finished coating. It can also affect the health and safety of your employees as well as the profitability of your business.
Where Should the Temperature Sensor Be Located on My Spray Booth?
RTT recommends that the temperature probe be in the discharge ductwork of the Air Make-up Unit (AMU). The probe is to be located as far from the discharge location of the AMU as possible before entering the paint booth intake plenum. This configuration helps to avoid sharp spikes in temperature and will even out the ramp and soak time of the burner. Eliminating the possibility of an over-temperature situation inside the AMU. In rare instances, the temperature probe may be in the intake plenum of the spray booth. Please consult with RTT Technical Support before locating the temperature probe anywhere other than the AMU discharge ductwork.
Where Should the Temperature Sensor Be Located on My Oven for Accurate Cure Readings?
The oven temperature probe is located as a standard design between the return air of the heater box and the exhaust fan of the oven. During the initial commissioning of the oven, RTT recommends using a separate device capable of recording temperatures within the oven (such as a DataPaq) to compare the oven temperature probe to actual temperatures within the oven It may be possible after evaluating the testing report the probe location may need to be changed to better read the average air temperature of the oven.
My Spray Booth and Oven Controls Require a Password to Change Settings - What Is It?
CT/CTC AMU – All passcodes provided in the RTT Booth & AMU Detailed Start-up Guide).
Operator passcode is 2050
Oven – All passcodes in the Oven Operation & Maintenance manual. Maintenance passcode is 1111
What Is the Expected Service Life of a Powder Cartridge Filter?
The life cycle of any filter has many factors that directly affect its lifespan. These factors include moisture, housekeeping procedures, velocity of air traveling through the filter, type of media being filtered and environment. The 80/20 cellulose cartridge filters supplied by RTT for your equipment is expected to be in operation from 3-12 months depending on these factors.
My Exhaust Fan Is Not Running Even Though My Booth Has Power — What Could Be Causing It?
There could be several issues that could cause your exhaust fan not to operate. If you have confirmed you have power, do you have a fault on your Variable Frequency Drive (VFD)? Check to see if there is a fault code displayed on the VFD. Depending on the make and model of your VFD these codes can differ.
How Can I Heat My Spray Booth During Spray Mode Using My Air Makeup Unit (AMU)?
All air make-up units provided by RTT Finishing Solutions can heat the air in spray mode but only to a limited temperature. All that is required is for the booth controller to be set to WINTER mode. This will allow for the AMU to ignite the burner even in spray mode.
Questions About Ovens and Control Systems
What Does the LOC Code Mean?
• LOC 2: No establishment of flame within the safety time
• LOC 3: Air pressure fault
• LOC 4: Extraneous light detected
• LOC 5: Air pressure welded in working position
• LOC 6: Actuator fault
• LOC 7: Loss of flame
These alerts help protect the system and ensure proper burner performance.
Why Does the Burner Shut Off and Return to Purge Mode?
This typically indicates a failed air switch.
Your system uses air switches on the combustion fan, recirculation fan, and exhaust fan.
If one of these switches does not provide airflow, the system returns to purge for safety.
Why Does My Oven Overshoot the Set Temperature?
Temperature overshoot commonly relates to the burner actuator not opening correctly. Check the following:
• Confirm the actuator shaft markings to verify it is opening 100% after ignition.
• Ensure all linkages and set screws are tight. Over time, set screws may loosen, allowing the actuator to turn without fully turning the shaft.
What Is the Required Gas Pressure?
Your oven should operate with gas pressure between 2 PSI and 5 PSI.
Pressures outside this range may affect burner performance or safety.
How Far Should the “H” Slots Be Opened on the Ductwork?
The “H” slots must be opened at least 1.5 inches to maintain proper airflow and system balance.
How Do I Download Temperature History?
You can download temperature history directly from the Smart Control panel:
1. Open the Maintenance tab
2. Select Temperature History
3. Click Export
4. Follow the on-screen instructions to save the file
What Is the Proper Incoming Gas Pressure for the Valve Train and Burner?
Proper gas pressure is critical for safe and reliable operation.
• Gas pressure must never exceed the maximum rating of the valve train regulator.
• Excess pressure can damage internal components or prevent the valve train from shutting off gas during a shutdown, creating a serious safety hazard.
• Too little pressure reduces burner BTU output and may cause low-gas safety faults.
Typical pressure ranges:
• Ovens: 2–5 PSI
Questions About Air Makeup Units (AMU)
What Is the Passcode for My Air Makeup Unit (AMU)?
The standard operator passcode for the Air Makeup Unit (AMU) is:
• Operator: 2050
Where Should the Discharge Temperature Sensor Be Located?
RTT recommends placing the temperature probe in the AMU discharge ductwork, as far from the discharge point as possible before the air enters the paint booth intake plenum.
This placement:
• Prevents temperature spikes
• Ensures accurate temperature control
• Minimizes risk of over-temperature conditions inside the AMU
In rare situations, the sensor may be placed in the booth intake plenum. Contact RTT Technical Support before doing so.
Is Incoming Gas Pressure to the Valve Train and Burner Important?
Yes, proper gas pressure is critical for safe and reliable operation.
• Gas pressure must never exceed the maximum rating of the valve train regulator.
• Excess pressure can damage internal components or prevent the valve train from shutting off gas during a shutdown, creating a serious safety hazard.
• Too little pressure reduces burner BTU output and may cause low-gas safety faults.
Typical pressure ranges:
• AMUs: 1.5–2.5 PSI (varies by design; refer to drawings/manuals)
• Ovens: 2–5 PSI
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