Describe the purpose and the different modes of operation of the system main relays.
What will be an ideal response?
The HV ECU controls the operation of the system main relay (SMR) to connect and disconnect the power source of the high-voltage system. Initially SMR1 and SMR3 are turned on to energize the circuit for the HV battery to provide the required current for the motor generator to start the engine. Then SMR2 is energized and SMR1 is turned off to make the current from the generator flow through a resistor, thus controlling the amount of current flow. SMR2 is turned on and SMR1 is turned off to allow free flow of current in the circuit. During shutdown, SMR2 is turned off first, then SMR3. This provides a means for the HV ECU to verify that the relays have been properly turned off.
You might also like to view...
____ between the evaporator cells allow air entering from the edges of the ice to travel along the entire ice slab and relieve the suction force.
A. Space holes B. Weep holes C. Release spots D. Weep space
When powers of 10 are to be multiplied, ____ their exponents.
a. add b. subtract c. multiply d. divide
All of the following are part of cylinder reconditioning EXCEPT ____.
A. resurfacing B. boring C. honing D. sleeving
HVACR technicians use tools that compare pressure to atmospheric pressure. What is this type of pressure called?
A) Column pressure B) Gauge pressure C) Absolute pressure D) Arometric pressure