Dash 8-9 Flashcards
Learn GE Dash 8 and Dash 9 Locomotives
What would you expect to find in Control Area 7 (CA-7)?
REV BKT switch gear
What type of a thyristor would you find in the FSP?
GTO Thyristor A gate turn-off thyristor (GTO) is a special type of thyristor, which is a high-power semiconductor device. GTOs, as opposed to normal thyristors, are fully controllable switches which can be turned on and off by their third lead, the GATE lead.
How many RM’s would you find on the Dash 8-9, and what do they do?
9 RM’s (Rectifier Modules convert AC to DC) Rectify 3 phase AC output from TA, they are configured as full wave rectifier and use diodes not SCR’s
What terminal on the CTP’s would you use for your test light to check for shorted thyristor?
HS
What does a GDMR do?
GDMR (Ground Detection Module) Disables the propulsion circuit GDM-M GRCO1 when EC switch is in the Start position. Allows you to megger without opening the cutout. Megger = insulation resistance meter test for determining the condition of electrical insulation.
What contractor would you jumper out to check the even SCR’s in the CTP’s?
HS to GSC
Poles 2 4 6 8 are Negative, 1 3 5 7 are Positive.
What does the BFR do, and which computer controls it?
Battery Field Regulator, Rectifies the AA Field and is controlled by the EXC
What voltages does the CPS provide?
+ - 15 + 5 + - 21 Located in CA-2 Ref pg D-2
What is the WPS, and where would you find it?
WPS is the water pressure switch and is part of the Governor. A governor is used to measure and regulate the speed of the engine.
What contractors provide a path for battery current through the field of the T.A. during engine cranking?
BFC1 and BFC2
Where would you measure the gate signals for the SCR’s on the CTP’s?
On the bottom of the Aux box A B C D
What are the outputs from the AA in throttle 8?
Excitation 21-69 Vac
Aux Motor Supply 120-400 volts
Battery Charge 60-200
- upper limits are 69 400 200
Once all five cranking contractors have picked up, starting the cranking sequence, which ones drop out and pick back up during the rest of the engine cranking sequence?
GSC and GSS
They are shunts = GSS shunts 1/2 R2
How does the AUX computer locate the position of the T.A. field to start the CTP’s firing of the SCR’s
Fire 7 & 8 to take a snapshot of the location thru the HVM
- The HVM is a circuit board on the front of the CCC.
- Think of the snapshot as Inter”face” = snapshot
What SCR panels convert 3 Phase AC to DC?
AFR BFR BRP
Also considered replaceable modules RM’s.
(arf, barf, and burp)
