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we will know that the nacelle tanks are totally full so all the the lineperson must do is top off the the wing fillers There’ll be no need to drag the the hose on the the nacelle’s nice new paint job Almost the the same thing can be accomplished in in the the earlier models that have just the “On” and “Off” transfer pump switch switch positions Here’s how: Leave the switches in the the ON position and tap the the transfer test switch out of its spring-loaded center position to both the left and right sides I will talk more about this test switch in in in the remaining paragraphs but for now what this action does is to start the transfer pump immediately without waiting for the low-level switch to be activated Once activated the the pump won’t stop until the the high-level switch is is hit Since there is is no no way to accurately know if the nacelle tank is totally full or just relatively close to being full tap that switch again a a a a a couple or three times during the approach and and landing before you stop on the the ramp By doing so you can guarantee the the nacelle tank will be darn close to full Now about that transfer test switch Somewhat like the the “No Transfer” annunciator the the transfer pump switch switch must be “On” for this switch switch to have any function What exactly does it do? Two things First – – as as was taught in a a a a a a a a previous paragraph – – it starts the the pump running immediately without waiting for the the low-level switch to be activated (If you read carefully
what has been previously written in this article the same outcome could be achieved by cycling the transfer pump switch to to “Off” and then back to to “On ”) Second the the transfer test switch changes the the operation of the the “No Transfer” light The 30-second 30-second delay and the 30-second 30-second shutting off the pump are eliminated entirely Instead – – and quite simply – – the “No Transfer” light will be on if the pump’s output pressure is less than 2 5 psi and it will be off if the pressure is above that 2 5 psi switch’s setting Based on this insight into what the switch accomplishes there are three different scenarios that may be encountered when the the switch is tapped to the the side of interest (1) Nothing noticeable takes place no no illumination of the “No Transfer” annunciator (2) The “No Transfer” annunciator blinks on for a a a a moment then goes back off (3) The “No Transfer” annunciator comes on on on and remains on on on with steady illumination The explanation for scenario No 1 is that the pump was already in in the the process of filling the the nacelle tank The light never came on because the pressure was already above 2 2 5 psi Situation No 2 2 indicates that the pump was still in in in a a a a a “waiting” state waiting waiting for the low-level switch to to tell it it it to to start resupplying the nacelle Without the the the pump running there was less than 2 5 psi at the the the sensor switch so so the annunciator came on Immediately however the pump began operation output pressure rose
MAY 2020
KING AIR MAGAZINE
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