"FREQUENTLY ASK QUESTIONS"
Your Tanis Engine Preheater & Ground Fault Interrupter (GFI) Outlet Issues
At times in the late fall and early winter we get calls about the Tanis engine preheater tripping the GFI outlets in hangers. In the past this was seldom a problem because:
- Hangers were not routinely equipped with GFIs.
- Tanis preheaters were generally plugged in most of the time.
WHAT IS HAPPENING?
- New construction and updated wiring codes dictate the use of GFIs.
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Moisture issues devlop over time, primarily in the cylinder elements when the potting compound cracks from the heat & vibration of engine operation. The ceramic heating elements may then absorb just enough moisture to trip a ground fault outlet. (Less than 1/500 of an amp)
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Tanis Preheaters are not recommended to be used continuously unless the aircraft is flown weekly. This allows moisture to develop.
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Operation of the Preheater dries out the ceramic elements resulting in normal preheater operation.
IF YOUR GROUND FAULT HAS TRIPPED FROM CONNECTION OF YOUR TANIS PREHEATER AND YOU CANNOT DETERMINE THE CAUSE:
Plug the preheater into a non-ground fault outlet for several hours.
This cures 98% of the problem.
Other solutions: Operate it on a generator.
Or, if it is a nice day, fly. This will warm and dry the cylinder elements
MORE PERMANENT SOLUTION:
- Get the system dried out & working.
- Reseal the elements with silicone sealer to prevent the moisture from causing the same problem next year.
NOT RECOMMENDED:
In desperate situations some pilots have used a 3 prong to 2 prong ungrounded adaptor (cheater) on the end of their extension cord. Since the plane is not grounded because of the rubber tires, the ground fault is not tripped. The GFI outlet would still protect a person from electrocution because it compares the amps out on the hot wire to the amps returning on the other neutral wire. However there is a possibility that the airframe could be at some voltage above ground (Usually around 60 volts), which can give a shock & possible spark hazard.
MORE INFORMATION: A good article of how the GFI works can be found at GROUND FAULT INTERUPTER INFO
TEN MOST COMMON QUESTIONS:
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How does it work? Tanis engine preheat systems work on the principal of a) heating the cylinder head and b) adequate heat without dependence on thermostats. Even if an engine starts, inadequate preheat means poor oil flow and engine damage. Tests prove that, unless the cylinder is heated, it will take a very long time and a cover to adequately heat the cylinder.
Can I leave it on all the time? Although it is not normally recommended, many people do leave their Tanis systems operating for long periods without corrosion problems. The key is to fly often and to run your engine at at least 180° F to burn off water in the oil. It is more important to not have the system turning on and off at frequent intervals. Heating and cooling creates condensation. A tip that will reduce humidity in the engine is to remove the oil dipstick and allow warm engine air (with the moisture) to rise through the oil filler tube and escape. Flying often keeps re-oiling shinny metal parts.
- What does it cost? Tanis systems vary based on the number of cylinders and type of preheater. Basic Tanis systems for 4 cylinder engines run less that $400.
- How many watts? Tanis systems are specifically engineered for each engine configuration so that wattages vary. However, as a general rule, Tanis systems have 50 watts per cylinder and 120 watts on the oil sump or crankcase. Super systems are available with 100 watts per cylinder.
- Should I use a cover? Covers are recommended for all types of preheat systems. They help prevent temperature changes, which could lead to condensation at certain temperature ranges. They are also very useful when traveling. A good custom fitted cover can keep an aircraft warm on the ramp for up to four hours.
- How long does it take to install? As a rule, you should allow 3-4 hours for installation.
- How long should I plug it in before I fly? Obviously this depends on the outside temperature and if the engine is covered with an insulated blanket. The easiest procedure to follow is plug it in 4 hours before you fly or the night before you intend to fly. Tanis systems will heat the engine above ambient 10 to 15 degrees per hour.
- When should I plug it in? We recommend when the temperature drops below 40° F, the engine should be preheated.
- How do I order Tanis products? Since Tanis has a strong FBO support program and a licensed mechanic should install the system, we recommend you order it through your FBO. Although anyone can order Tanis preheat systems on line, we recommend you consult with one of our staff before ordering because many engines have a slightly different system. Every system is specifically engineered for the engine’s unique preheat requirements.
(Q) Why doesn't the price list specify, injected, turbo, geared, etc?
(A) It does not make amy difference to the heater if the engine is turbo, injected ,geared, etc.
(Q) What is the STC number?
(A) No STC is required as it is a minor alteration.
(Q) Do I need a Form 337?
(
A) No, a Form 337 is not needed. A log entry by an AP mechanic is needed.
(Q) How is the preheater approved?
(A) Not functional during flight, no-hazard basis, minor alteration, installed by FAA licensed mechanic,
and a log entry made.
INSTALLATION:
(Q) Can I install the preheat myself?
(A) Yes but it must be signed off by a A&P mechanic.
(Q) How long to install preheater?
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A) 2 to 3 hrs for 4 cylinder, and 4 to 4.5 hrs for 6 cylinder (per engine)
(Q) How are the pads bonded on?
(A) Kit comes with the sealant to bond on pads.
(Q) Are instructions included.
(A) Yes instructions and Drawings.
(Q) What is the installed weight?
(A) The installed weight is on the instructions.
(Q) Cylinder Probe will not fit.
(A) Hole was not reamed out on older cylinders.
