Published October 2007

Working Wireless

By Erik Gunn (page 52)

IntelAControl adds operator convenience and efficiency in operating the trailer-mounted 3518-SC jetter from O’Brien Mfg.

Waterjetting is a highly effective way to clean and maintain sewer pipes. Efficient jetter operation is important, and so is safety. The high water pressures at which jetters operate — often 4,000 psi or more — demand the utmost care.

Until fairly recently, jetter operators have worked from a control panel onboard the truck or trailer on which the jetter is mounted. Often, manholes are located some distance from where the jetter can be positioned, so operators have had to use two-man crews or spend much of a session walking between the manhole and the machine.

Remote control enables operators to control the machine while standing at a considerable distance. This is especially useful if the operator wants to be at the manhole, but still wants to control the machine directly, rather than relay commands to a co-worker at the machine-mounted controls. It also enables the operator to stand safely away from the hose itself.

O’Brien Mfg., a unit of Hi-Vac Corp. based in Marietta, Ohio, makes a line of trailer-mounted jetters and offers IntelAControl remote operation for its machines. Expert Plumbing, a contracting firm in New Lenox, Ill., owned by Kevin Brennan, took delivery of an O’Brien 3518-SC single-axle trailer on July 17.

The next day, Brennan employees put the new machine to work, cleaning a sewer lateral and a stretch of connecting main on the company’s property to prepare for cured-in-place pipe (CIPP) lining. Mike Kampenga of Expert Plumbing demonstrated the unit, assisted by Jeff Fulton, product sales manager with O’Brien Mfg.

Walk-around

The 3518-SC trailer jetter carries a 350-gallon water tank and a pump system capable of delivering 18 gpm at up to 4,000 psi. The jetter has a rear-mounted hose reel loaded with 450 feet of green sewer hose and a 20-foot black lead hose. The lead hose is a safety device that helps users withdrawing the hose from the manhole see when the jetting end is about to e­merge. The pump, made by Giant Industries Inc., is powered by a 65-hp, water-cooled Cummins diesel engine. The jetter comes equipped with a toolbox.

The IntelAControl system includes a fixed-control panel mounted at the rear of the jetter to the right of the hose reel, and a portable, remote- control unit. The jetter-mounted panel includes plastic membrane buttons that control the reel motor and the jetter pump and throttle. It also has an emergency shut-off switch and a button to shift operation from the control panel to the remote-control unit.

The panel is installed with four bolts and two modular electrical connections, making it easy to repair in the event of a malfunction. “The control panel can be replaced in 10 minutes,” Fulton says.

There are two digital readout screens, one above and one below the main controls. The upper screen switches from monitoring oil pressure and engine temperature to water pressure when the jetter is pumping water. The lower screen monitors hours of operation and pump speed (rpm).

The jetter includes a feature that detects when the tank water level is low and automatically switches the system to bypass to prevent pump damage from running dry.

The remote unit is small enough to fit comfortably in the operator’s palm. A belt clip enables it to be stored when not in use. The unit has buttons for the jetter pressure, the hose reel direction (in or out) and speed, and the emergency shut-off. It is powered by a 4.2-volt, lithium-ion battery that can be recharged either from a vehicle cigarette lighter or from one of two 12-volt, 20-amp receptacles on the control panel. An LED on the remote lights orange if the battery is low, and red when the jetter is sending pressurized water through the hose.

The battery has a rated life of four years. Like the batteries in many cordless and cellular telephones, users are instructed to let it drain fully before recharging. The remote itself is rated for a range of up to 750 feet.

To save battery power, the remote’s on/off switch will automatically power it down if it has not been used for five minutes.

Operation

Kampenga used the jetter to clean two stretches of sewer line, both accessed by a manhole on a private sidewalk outside the Expert Plumbing offices. The first line was a 36-foot, 6-inch lateral connecting to the mainline. The second line was an 85-foot stretch of 8-inch mainline leading to another manhole near the street. The mainline was designated for the CIPP repair.

Kampenga backed the jetter into position about 70 feet from the manhole to the sewer lines to be cleaned. After attaching the jetter nozzle, he started the jetter from its fixed, onboard control panel. Initially the jetter idled in a recirculating mode, which moves water through the system, but not into the jetter hose and not under high pressure.

He manually unreeled the hose and fed it down the manhole and into the sewer. Kampenga used the control on the fixed panel to switch control of the machine to the portable remote unit, then used the remote control to feed the jetter hose into the lateral line. Using the remote to switch the machine into the jetting mode lit a red LED on the remote. Kampenga raised the pressure to about 2,000 psi, and fed the nozzle in the 36-foot distance to the main.

(As delivered, the jetter was not equipped with a footage counter, although that feature is available. Kampenga relied on his experience at jetting to know when he had reached the proper distance. After the observation, Expert Plumbing had an O’Brien Mfg. IntelACount digital hose counter installed on the jetter.)

Once the hose had reached the tie-in, he used the remote to throttle up the pressure to 3,200 psi, and to reel the jetter back to the manhole. When the black leader hose appeared, signaling that the business end of the jetter was almost out of the pipe, Kampenga throttled the pump down to idle.

He then fed the jetter nozzle into the mainline going the opposite direction and repeated the process, bringing the pressure back up to 2,000 psi for the outbound trip. When the nozzle reached the end of the 85-foot stretch of the main at the next manhole, Kampenga increased the pressure and reeled back the jetter.

A camera inspection of the cleaned lateral section revealed a small blockage still remaining, so Kampenga repeated the jetting procedure. He used a pole-mounted screen catcher to collect the debris in the area below the manhole.

Kampenga then demonstrated the machine’s emergency shut-off, pressing the red shutdown button on the remote unit. The jetter engine shut off immediately. The jetter’s lower display screen then toggled between two messages: “Emergency Off. Engine Shut-down” and “Turn Key Off to Restart.”

Observer comments

The handheld remote unit looked easy to hold and operate, and responded instantly to the operator’s commands. The remote enabled Kampenga to walk some distance from the control panel and still put the jetter through all of its paces. The remote has a simple and easy-to-follow design. It lacks a separate information readout, so operators who want digital data from the control panel have to walk back to the machine to get it.

Manufacturer/user comments

Kampenga noted that he can gauge jetter speed by ear, so he did not regard the absence of indicator screens on the remote as a problem. Fulton said that to transmit information from the machine to the remote would require a two-way wireless signal and therefore a substantially larger, bulkier and more expensive remote unit.

During the entire jetting procedure, Kampenga found the remote unit immediately responsive. “I never lost the signal,” he said. Contact with the base panel was broken once, but not because of distance. Fulton explained that Kampenga had sent two conflicting instructions to the hose-reel motor in rapid succession, first pressing the button to reel out, then immediately correcting himself and pushing the button to reel the hose in.

The remote unit has a two-second delay built in for safety reasons, Fulton said, and if two conflicting signals are sent from it within that two-second period, the machine is designed to ignore them both and to reject all further communication from the remote. “What you have to do is turn the remote off and then power it back up,” Fulton explained. The jetter’s control panel switch is used for that purpose. Experienced operators soon learn that if they press the wrong button and want to override the instruction they’ve just given, they can simply wait two seconds.

Kampenga said he has used the system in test situations up to 300 feet from the jetter with no loss of signal.

Brennan of Expert Plumbing said he looked forward to using the jetter and its remote capability. There are many situations, he said, in which “you can’t get direct access to the manhole. There are instances where we’ll stretch 100 feet of hose to get to a manhole.” He expects the IntelAControl system to be especially useful in such cases.

Fulton said O’Brien conducted extensive tests to ensure the sturdiness of the remote unit. “We actually dropped one down a septic tank, left it there for a day, then removed it and dried it out per the instructions. It fired right up.”

COLE Publishing invites manufacturers of innovative equipment to provide demonstrations of their technologies for reporting in this monthly feature of Municipal Sewer & Water. To arrange a demonstration, e-mail editor@mswmag.com or call 800/257-7222.