PREDATAIR Hydraulic Above Deck

Features and Benefits
Applications
Operating Principles
Routine Maintenance
FAQ

Features and Benefits

Direct Driven Rotary Screw Compressor

No belts to adjust or replace.
100% Duty Cycle

Smallest and Lightest in its Class

More space for tools and other equipment.
More payload available

Integral Hydraulic Oil Cooler

No need for an external hydraulic cooler if you are only installing the compressor system.
Uses over-sized cooler to maintain low hydraulic temperatures

Hydraulic and Compressor Oil Temperature Sensing

Protects the compressor from overheating.
Cold start protection for the hydraulic motor and cooler.
Prevents hydraulic oil from overheating.

Soft Start Feature

Reduces load placed on the hydraulic system during the compressor startup.
Increases compressor life

Air Pressure Unload Circuit

Reduces air pressure when not using air but the system is on.
Reduces thermal load when the compressor is not in use.
Reduces fuel consumption on truck.
Increases compressor life

Hydraulic Standby Mode

Turns off hydraulic oil to the motor when air is not being used.
Will automatically re-start when air is required.
Delay is adjustable via the remote control box.
Reduces thermal load when the compressor is not in use.
Reduces fuel consumption

Built In One-Way Check Valve

No need to purchase when installing an air reservoir tank.
Protects the compressor system from contamination from downstream sources

Throttle Enable Lead

Allows use of second throttle speed.
Drops truck engine back to base idle when not using air

Above Deck Mounted

When properly maintained, VMAC compressors should last for the service life of your vehicle.
Your truck hydraulic system powers the compressor. There are no additional engines to maintain or carry additional fuel for. Again saving you time, money and energy
Easily transferable to new service truck body

Applications

Service Trucks:

½” – 1 ¼” impact wrenches
air grinders and sanders
air starters for large machinery
other pneumatic tools

Tire Service:

filling tires
pneumatic torque wrenches
air jacks
other pneumatic tools

Mobile Mechanics:

welding systems (air gouging)
other pneumatic tools (impacts, grinders & drills)

Fire Apparatus:

compressed air foam systems
other pneumatic tools
Light & Heavy Construction:
concrete breakers
jackhammers (up to 90 lbs.)
moles
other pneumatic tools

Mining:

air starters for large machinery
½” – 1 ¼” impact wrenches
other pneumatic tools

Landscape Construction:

flushing sprinkler systems
other pneumatic tools

Lube Trucks:

lube systems (pneumatic pumps and air actuated switching valves)
other pneumatic tools

Public Utilities:

moles
opening & closing water valves
jackhammers (up to 90 lbs.)
air lines to aerial buckets
post pounders for signage and guardrails
grinders
snow wands
tires
sand blasting
tampers
other pneumatic tools

Railways:

track maintenance and repair vehicles
snow wands for switch clearance
1 ¼ impacts for tracks & switches
spike drivers & pullers
jackhammers
brake checks
other pneumatic tools

Operating Principles

The PREDATAIR is ready to produce air with your supply of hydraulic power. Simply connect your pressure and return lines to the hydraulic manifold on the PREDATAIR and you’re ready to go. Of course you’ll need between 9 and 14 GPM to for the PREDATAIR40 and between 13 and 20 GPM for the PREDATAIR60, depending on your air CFM requirements.

Once you have the hydraulic fluid running through the system, turn the compressor on with a 12-volt power source and the integral digital control takes care of the rest. A 12-volt solenoid will open and allow the hydraulic oil to travel into the hydraulic motor, thus starting the compressor. The motor is directly coupled to the compressor via a SAE B spline drive. Unlike other above deck compressors, there isn’t a belt or pulley system. Once the oil travels through the motor it is cooled within the integral cooler. A 12-volt fan cycles with the temperature of the compressor to keep things cool.

The cooler provides cooling for the compressor oil, as well as your hydraulic oil. There is ample cooling to keep the system cool, if the compressor is the only component running. Additional hydraulically powered equipment may require separate cooling sources.

The compressor itself works just like the VR70 UNDERHOOD compressor. Compressor oil is injected into the rotor housing to provide a seal between the rotors. The oil/air mixture then flows into the air/oil separator tank where baffles and air direction changes remove much of the oil from the air. A coalescing filter at the discharge end of the tank then removes the majority of any oil left in the air stream. The oil then travels through the cooler and is returned to the compressor to once again provide the seal between the rotors.

The inlet control valve works in the same fashion as the UNDERHOOD compressors as well. When the system reaches full pressure, the inlet will close and prevent further air from being brought into the system. A pressure drop caused by the use of your tools will then tell the inlet to open and generate a steady flow of air equal to your requirements.

Traditional safety systems are incorporated into the PREDATAIR. A 200 psi safety valve is located at the back of the tank to prevent over pressurizing the system. As well, a temperature probe will send a signal to the control box to shut the system down if an over-temp situation occurs. On the hydraulic side, a 2,650 psi safety valve prevents too much hydraulic pressure from entering the system.

The digital control box controls not only the on/off function, it also controls the cycling of the electric fan, monitors regulated system pressure to activate the Speed 2 wire if used and monitors the compressor oil temperature. If the oil becomes too hot, the system will shut down and if the compressor oil is too cold, the system will not turn on until the oil heats to a sufficient temperature.

The PREDATAIR combines all of these features in a very compact, light weight package that delivers up to 40 CFM or 60CFM of air for your job.

Routine Maintenance

You must use VMAC compressor oil in this system. Failure to use this oil will result in damage to the compressor and may void your warranty!

The rotary screw compressor is designed and machined to exacting tolerances. Foreign particles entering the system will drastically damage or shorten the life expectancy of the compressor and will result in damage to bearings, gears, rotors and the inside of the housing.

The system filters enhance performance and extend component life by reducing damage from dust and other debris. Check the air filter frequently to ensure that it is not restricted or damaged. Proper filter maintenance is the key to long compressor life.

Regular, scheduled maintenance is required. This includes:

inspecting the air cleaner and maintaining the oil level
500 hours or 6 months service
more frequent service in severe operating conditions
Service kits are available for 500 (A700156) hour service intervals. Oil, air filters, oil filters and other replacement parts can be ordered. The PREDATAIR is equipped with a standard air filter. Heavy duty air filters (standard A700136 and cyclonic A700138) are available if the system is operated in an extremely dusty environment or is installed in a cabinet or enclosure, as this will improve performance by providing cooler ambient air.

Adding Compressor Oil

You must use VMAC compressor oil. Failure to use this oil will result in damage to the compressor and may void your warranty.

Replacing the Air Filter

If the system has been just operated, shut it off and wait at least 30 seconds for the air pressure to vent before working on the system.

Clean loose debris from the area around the filter cover to prevent contamination entering the compressor.
Remove the filter cover retaining nut, the filter cover and the filter element.
Immediately cover the air inlet opening to prevent contamination. Do not use compressed air or perform any other tasks around the compressor until the filter and cover are replaced.
Clean the inside of the filter cover with a clean, dry cloth. Do not use flammable solvents to clean the inside of the cover. If you do use solvent, rinse the inside of the cover thoroughly with fresh water and dry it before installing the cover.
Remove the intake covering and install a new air filter. Make sure that the filter fits over the machined step on the housing.
Replace the cover and secure it with the cover bolt. Do not over tighten the bolt. Never attempt to clean the filter element with compressed air. Replace the filter element.

Changing Oil and Filter

If the system has been just operated, shut it off and wait at least 30 seconds for the air pressure to vent before working on the system.

Caution: Do not attempt to change the oil filter until the oil has cooled. Hot oil can cause severe burns.

Caution: Never over-tighten the filter, as this may damage the seal or the filter.

Clean the area around the oil drain plug and the filter on the tank to prevent contamination.
Remove the drain plug and drain the oil, then install and tighten the plug.
Slide a thin drip tray or absorbent material under the filter to collect oil spills. To prevent damage, always use a proper filter wrench.
Remove the filter by turning it counterclockwise. Before discarding the filter, check to make sure that the threaded nipple did not unscrew with the filter. If the nipple is in the filter, remove it carefully to avoid thread damage and replace it in the tank housing.
Check the gasket-sealing surface on the front of the tank for contamination, old gasket material or damage.
Apply a thin coating of compressor oil to the filter-sealing gasket and fill the filter with new oil.
Spin the filter onto the threaded nipple until the gasket contacts the sealing surface on the tank, then tighten the filter an additional 3/4 to 1 turn to seat the sealing gasket.
Remove the fill cap and pour VMAC compressor oil into the oil fill hole on the compressor tank using a funnel.
Check the level in the sight glass at the front of the tank. Continue adding oil until the level is up to “MAX”. Do not overfill the system. Overfilling the system with oil can flood the sight glass window and make the system appear empty.
Replace and tighten the fill cap.
Activate the hydraulic system.
Turn the compressor switch on the control unit to the “ON” position.
Allow the system to pressurize and operate for a few minutes.
Turn the compressor off, check for oil leaks and check the oil level. Add oil as required.

Changing the Coalescing Filter

If the system has been just operated, shut it off and wait at least 30 seconds for the air pressure to vent before working on the system. Also allow sufficient time for the oil to cool.

Caution: The discharge cap is under spring tension.

Clean the back of the tank to prevent contamination.
Remove the drain plug and drain the oil, then install and tighten the plug.
If you are replacing the oil filter, follow filter replacement procedures.
Disconnect the air outlet line and teflon lines from the back of the tank.
Remove the bolts holding the discharge cap from the back of the tank and remove the cap and small spring.
Remove the coalescing filter and spring from inside the tank. Check the inside of the tank for any evidence of metal filings or contamination; if found, flush the tank, hoses and cooler. Metal filings will damage the compressor.
Remove and discard the O-ring seal and the rear cap seal; replace them with new parts. If you use solvents for cleaning, thoroughly rinse the parts with hot water to remove all solvent residues.
Clean the thimble screen spring and clean or replace the thimble screen.
Thoroughly clean the large spring and spring plate. Remove any rust or contaminants.
Install the large spring and a new coalescing filter. Make sure that the spring is in place, as it holds the coalescing filter tight against the rear cap seal.
The large spring also prevents electrostatic buildup by grounding the coalescing filter. If the spring is not installed, an electric arc may occur, which could resultin an explosion, potential tank rupture or fire.
Install the discharge cap and torque the bolts to specifications.
Install the lines on the back of the tank.
Remove the fill cap and pour VMAC compressor oil into the oil fill hole in the compressor tank using a funnel.
Check the level at the sight glass at the front of the tank. Continue adding oil until the level is at “MAX”. Do not overfill the system. Overfilling the system with oil can flood the sight glass window and make the system appear empty.
Replace and tighten the fill cap.
Activate the hydraulic system.
Start the system.
Allow the system to pressurize and operate for a few minutes.
Turn the compressor off, check for oil leaks and check the oil level. Add oil as required.

FAQ

Is the PREDATAIR my simplest option to get high performance compressed air delivery?
How complete is a PREDATAIR as a ready to run product?
What tools will the PREDATAIR typically run?
How much hydraulic power is needed to run the PREDATAIR?
Do all trucks have a PTO port ready to take a PTO?
What is the install time for PREDATAIR?
Does the PREDATAIR add to the thermal load of our hydraulics?
Does the PREDATAIR require an air receiver tank?
Does the PREDATAIR include a FRL and is it necessary?
Does the PREDATAIR remove water from the compressed air?
What is the best location to mount a PREDATAIR?
What applications typically use the PREDATAIR?

Is the PREDATAIR my simplest option to get high performance compressed air delivery?

If a VMAC UNDERHOOD belt-driven compressor system does not apply and the truck is equipped with hydraulics, then the PREDATAIR is an excellent choice.

How complete is a PREDATAIR as a ready to run product?

VMAC supplies a self contained, self-cooled compressor unit, which has a hydraulic motor inside it. The PREDATAIR requires hydraulic power from a separate system typically powered from a PTO at the transmission and that includes a hydraulic oil reservoir. An air supply line is also required.

What tools will the PREDATAIR typically run?

Impact wrenches up to 1 ¼”, medium size jack hammers –as well as some efficient 90 lb hammers, chippers, air spades, etc.

How much hydraulic power is needed to run the PREDATAIR?

Flow range is 14 to 20 GPM at 2,100 psi. The pressure relief is set at 2,650 psi so the hydraulic PTO pump needs to be able to withstand that potential back pressure.

Do all trucks have a PTO port ready to take a PTO?

No, not necessarily, it may need to be specified when the truck is ordered.

What is the install time for PREDATAIR?

VMAC provides an installation guide for installers. Times range depending on other details that may be associated with the work required. The PREDATAIR™ itself involves only 2 hydraulic lines and 3 wires to connect. The air supply line (not supplied) also needs connecting.

Does the PREDATAIR add to the thermal load of our hydraulics?

No. The cooler built into the PREDATAIR™ cools the compressor oil and the hydraulic oil used by the compressor. Other hydraulic equipment in the circuit may require additional cooling.

Does the PREDATAIR require an air receiver tank?

No, but a tank is recommended to improve the running characteristics by decreasing cycling and improving fuel efficiency. The tank size required depends on applications and space availability.

Does the PREDATAIR include a FRL and is it necessary?

A Filter, Regulator, Lubricator is not included; however, it is recommended that every system includes at least a Regulator mounted before the air supply line. VMAC does offer an excellent ¾” FRL that matches the specifications of the PREDATAIR.

Does the PREDATAIR remove water from the compressed air?

No. As with any compressor, unless a moisture removal system is put in the supply line, the resulting air supplied is at or near saturation. Some applications may be concerned with moisture in air lines. To best remove water from the air stream, a VMAC ELIMINATOR may be required.

The ELIMINATOR works by cooling the air about 60 ° f -then through an automatic water dump valve it eliminates the condensate. It does all this with only a 1 psi drop in pressure, since it is optimized for systems up to 70 cfm. A receiver tank is another opportunity for removing excess moisture.

What is the best location to mount a PREDATAIR?

On top of a truck body or any location open to free air exchange. If placed in a cabinet the self-contained cooler in the PREDATAIR may not be able to keep up to the thermal load and the system may ‘over temp’ and shut down.

What applications typically use the PREDATAIR?

This product has been installed on Service Trucks, Utility Trucks, Mining Trucks and Equipment, BobCats –Any source of 14 to 20 GPM hydraulic power will work whether it is mobile or stationary.