Tech support call*

10/30/2017

Jim is a service technician at XYZ Equipment. He is working on an LSC light tower in which the lights will not function. Unable to diagnose the issue, Jim calls the Doosan Dealer Technical Support and Training hotline – (800) 633-5206 – for assistance.

Jim provides the model year, model name and serial number listed on the aluminum plate near the controls of the light tower. He also reads off the hour meter located on the control panel. The machine seems to operate properly apart from the lights failing to illuminate. Jim is asked a few questions to help identify the issue.

“What is your voltage reading at the receptacle?”

The receptacle is a common household configuration outlet. Jim finds the voltage reading is less than 120V. A reading less than 120V AC is indicative of a problem on the power generation side of the machine.

Jim is instructed to measure voltage at terminals 1 & 2 on TB1 to Ground respectively while the machine is running and taking appropriate safety measures. The readings show less than 120V AC on each respective terminal. This confirms that the generator is not operating properly.

Jim is instructed to test generator capacitor C5. The specified capacitor farad rating — typically denoted by μF — is shown on the capacitor and on the part number description in the Parts Manual. A lesson on how to test a capacitor is available online at Doosan Portable Power University.

Capacitors that measure more than 1μF below rating are the most common cause of inoperable LSC light tower lights. Capacitors can deteriorate over time. Adding capacitor testing to preventive maintenance routines can prevent downtime and costly loss of rental income due to a low-cost component.

Jim finds the capacitor reading is 23.2 μF, more than 1μF below the 25μF rating as specified. He uses the Online Parts Book to identify and order a replacement capacitor for the LSC light tower. Once the part has been received, Jim should consult the Doosan light tower manual for the proper replacement instructions.

*This scenario is a compilation of calls and is not intended to reflect an actual situation or identify real people.

Proactive training
Doosan instructor-led training covers operation, maintenance, service, safety, parts and warranty support of current light tower models in detail. Training results in quicker resolution and return of the machine to the customer or the rental fleet. The next session of Doosan Light Tower training is November 6-10 in Statesville, North Carolina. Log into Doosan Portable Power University website through PASSPORT for additional details and online registration information.