Liebert Notes Flashcards
A call for heat/cool is sent as input through the ________ which becomes an output (command)
microprocessor
Lieberts use industry standard triacs rated at a ___amp capacity
2amp
If a load is removed from the triac, you can get a false reading due to potential voltage. True or False?
True
On a Liebert, the gate connects the ______-_______
opto-isolator
The pin/dot on the opto-isolator represents?
Location of pin 1
Input pin 1 is ___volts
AC (24v prior and 1.2v at opto)
Output pin 1 is ___volts
DC (5vdc)
Pin one is the voltage being received by the opto. True or False?
True
Pin 2 on the input opto completes the AC source to ______/_______
neutral/ground
Pin 2 on an output opto completes the DC source to ______-_______
digital-ground
Input Opto has no voltage signal on what pins?
3,6
Pin 4 and 5 on input opto?
Pin 4 completes DC source to digital ground.
Pin 5 receives Dc signal to microprocessor (5v when not activated and 0v when activated)
Output opto has no voltage signal on what pins?
pin 3,5
Pin 4 and 6 have what function on output opto?
Pin 4 completes 24Vac path to gate of the triac
Pin 6 receives AC source signal from input device
Output Opto 1-2 pins are __v when conducting and __v when not conducting
0v
5v
Purpose of the opto-isolator is to provide isolation of ___ voltage sources
two
Opto-isolators allow a DC voltage to activate an AC load or allows an AC voltage source to provide a ____ signal
DC
Two types of Opto isolators are?
Input and Output Opto
Difference between input and output opto?
Input provides DC signal and Output allows DC source to activate an AC load
The output-opto uses a DC source to activate a ____ internal to the IC chip. This causes a triac, also internal, to switch on allowing current flow to the AC load
LED
What is the purpose of the ribbon cable on the leibert?
status and alarm lights
When is the hot gas bypass coil energized?
When evap press temp is too low, HGBV opens and allows hot gas to mix with refrigerant
Purpose of HGBV?
reduce cooling capacity and defrost coil
Humidifier pan fills with water based on ?
time (9.5min for 40sec)
The leibert filter clog is nuisance tripping. How to resolve?
disconnect the switch
The Leibert requires water in the infrared humidifier pan. How to make this happen electrically?
Put factory jumper on Q12
How is auto flush control accomplished on Leibert Level O?
Programming
INput-optos isolate what voltages?
a) AC voltage control of DC voltage
b) DC control of AC voltage
c) Are not used on Level O controls
a)
Output-optos isolate what voltages?
a) AC voltages control of DC voltage
b) DC voltage control of AC voltage
c) Are not used on Level O controls
b)
What device activates the gate of the triacs?
OPTO
What does EPROM stand for?
Erasable programmable read only memory
What precaution must be taken when checking bulbs of infrared humidifier lamps?
do not look directly at bulbs
What precaution must be taken when changing bulbs of infrared lamps?
Do not touch bulbs with bare hands
What device will prevent Leibert from starting immediately when power is resumed after a power failure? what is the max delay?
Sequential auto restart
0-90sec
