F7-Ovp Or Uvp Error - Toyotomi KURO Mini Service Manual

（15）F7-OVP or UVP error
Cause: All the inverter air conditioners are equipped with voltage
inspection circuits, but differnt models of machines have differnt
locations for the voltage inspection (on the modue panel or main
external control panel). When the supply voltage is lower than 135V or
Explanation of
higher than 275V, the inspectio circuit would detect over or under
voltage protection signal and send it to the main external control panel
error
and the main external control panel would raise the alarm "OVP or
UVP error" and indicate it through the internal motor.
Inspection path: supply voltage → internal direct current voltage →
reactor wiring → module panel → main external control panel.
Tools required
Multimeter
for inspection
Frequent
Supply voltage, reactor, moduel panel and main external control panel.
problematic part
1. First, check the supply environment of the user, especially shall
check when the compressor of the air conditioner has been running for
a while. The normal supply voltage shall be between 198V and 242V
and the minimum work assurance range of the air conditioner shall be
within 165V and 265V and it shall be especially noted that the voltage
value shall not be decreased significantly after running of the
compressor (voltage decreasing by over 25V), because if the supply
voltage is decreased by a lot, it means the supply line capacity is
insufficient and the user is usually suggested to replace the circuit or
install a specizlied air conditioner supply voltage stabilizer.
2. For the external machines with PFC panels (without separate
Inspection
rectifier bridges), the operator shall ensure if the PFC function is on
procedure and with the direct current voltage grade of the multimeter. When the
compressor is running, voltage between P and N ends detected on the
key points
test module panel or main external control panel shall be over 200V
and if the voltage is below that range, it is possible that the reactor is
faulted or the PFC is broken.
3. When the air conditioner is switched on, if the compressor is not
running but there is a alarm of "OVP or UVP error" and the power
voltage detected with the multimeter is not below 150V, it's probably
the voltage inspection circuit is faulted. The operator shall check and
confirm the voltage inspection circuit is on which control panel first
and then replace it. The regular replacement: for the external machine
of single panel single chip, replace the external controller directly; and
for the machine of two panels, replace the module panel.
For some models, OVP or UVP error signal is delivered through the
connector wires between the module panel and the main external
control panel, thus it is possible the voltage signal is not delivered
when the communication between teh module panle and the main
Special attention
external control panel is not good. It is possible that the error is fause
raised but after some minutes that the error is finally confirmed as
"Main external control panel and module pannel communication
error", which shall be specially noted.
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