Air starter systems present challenges in cold weather that are different than the challenges posed by electric, battery-charged engine starting systems. Every engine mechanic knows that cold weather can make their job more difficult. When temperature drops all engines may start up a little slower, but when that engine is a natural gas compressor on the side of a remote mountain or a tugboat floating on a frozen inland river, the job gets complicated. Starting your drilling rig or marine diesel engine in the cold can sometimes be a challenge but worry not… we have compiled five tips to get you through the toughest circumstances.
Engine Oil
Obviously, engine oil is not directly related to the air starter, yet it factors into how easily the engine starts, as does the ignition and fuel. Summertime engine oil weights often will not work in extreme cold temperatures. As part of the engine’s preventive maintenance program, the type of engine oil installed leading up to winter can head off trouble when temperatures take a sudden dip. Expecting the starter to overcome engine factors such as heavy oil viscosity and ignition complications can sometimes present a burden that the starter may not be able to overcome. Pushing the starter beyond its limit for prolonged time periods under adverse conditions could end in failure and frustration to be avoided.
Starter Lubrication
Vane air starters require lubrication of the air or gas stream. Make certain your vane starter lubrication system is topped off with lightweight non-detergent machine oil. While turbine air starters do not require air stream lubrication, their transmission gear case is factory-packed with special grease or transmission fluid, and these lubricants are affected by the cold temperature as well. Keep starter lubrication in mind before beginning an engine start cycle by allowing the unit to warm-up as much as possible.
Water in Supply Lines
Both air and natural gas supply lines often contain water or other liquid contamination. Supply line contamination can harm air starters throughout the year but will be especially troublesome once the moisture freezes. Ice can block supply lines before reaching the starter or obstruct internal air starter moving parts such as the vanes, rotors, turbine nozzles, turbine rotor air passages, or other air starter components. If possible, blow out supply lines before initiating wintry weather starts. Employ safe warming methods to relay valves or other supply line devices before commencing the start sequence. Avoid striking the starter with mallets or hammers as this causes unseen internal damage and can invalidate your warranty or exchange core.
Water vapor condensation at temperatures above freezing can cause problems as well. As daytime and night-time temperatures fluctuate, condensation forms causing rust, corrosion and sticking internal air starter parts. Periodic flushing of air line and starter systems will lessen trouble and prevent failed start cycles.
Avoid Prolonged Hard Crank Cycles
When an engine does not start, it can be frustrating in the best of conditions. Avoid long hard crank cycles. Keep your crank cycle to 10 seconds or less and pause for 10 seconds between attempts. If the engine does start after 3 failed attempts, a minimum five-minute cooling period is required as per your starter manual. Without this time limit for operation and an adequate cooling-off period, the starter will overheat and is likely to be damaged or suffer complete failure.
Manufacturers design and build air starters for heavy-duty industrial performance, but if pushed beyond their normal operating limits they can overheat and fail. Turbine air starters normally operate at 20,000 to 26,000 RPMs. These high rates of speed can generate extreme heat if the crank cycle exceeds recommended time limits and result in bearing failure…even in freezing weather.
Never Exceed Recommended Operating Pressure
When cold weather makes an engine tough to start, it may be tempting to apply more air or gas pressure. Operating any air starter above the indicated maximum operating pressure is absolutely discouraged. Exceeding maximum operating pressure will lead to complete starter failure, as well as invalidating your starter warranty or exchange core value.
Hopefully, these field tried and tested tips will help you start up your diesel or natural gas engine in the coldest winter weather. In general, operate your air starter according to the manufacturer’s instructions to avoid a complete starter failure that will only compound your cold weather hardship. For more advice or technical assistance contact MASCO.