Technical Support FAQ

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.

A: Several items need to be addressed to achieve a balanced booth that will also allow the AMU to consistently ignite the burner. “Start-Up” is a procedure that is done when the equipment is new at your facility. The “Start-Up” procedure involves dozens of steps checking distinct items to ensure things are operating properly. If “Start-Up” has not been performed on the unit, then it is highly likely that the booth will not balance. To resolve the issue, perform the start-up steps outlined in the RTT Booth & AMU Detailed Start-Up Guide located here (link to guide RTT Booth & AMU Detailed Start-up Guide).

Quick items to check:

Are any of the belts broken on any of the fans?
Are all the fans rotating the correct direction?
What is the booth pressure set point on the Carel controller?
Is the pressure sensing tube properly connected to the transmitter?
Is the damper (ARV) at the end of the exhaust stack opening?
Are the exhaust filters new?
Do the specifications of the exhaust filters match what has been supplied by RTT?
Are there turns/offsets in the exhaust ductwork?
What is the amperage rating of the exhaust fan and how many amps is it pulling at 60hz?

A: 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.

A: 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 Engineered 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.

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.

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.

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

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.

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.

All air make-up units provided by RTT Engineered Solution 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.