Toshiba MMY-MUP0961HT6P-UL Service Manual page 61

Item Description of operation, numerical data, and other information
13. Heat Since the refrigerant cooling heat sink cools the device by the refrigerant temperature of
sink the liquid pipe, if the liquid pipe temperature drops due to a gas shortage cycle, dew
condensation condensation on the device may occur.
prevention Therefore, the control is for the purpose of preventing dew condensation on the element.
control
1) Control condition
• Compressor ON
• Do not execute this control during startup control
• Do not execute this control during defrosting operation
2) Control content
During cooling operation, when TO-TL2 ≥ 5K is continued for 5 minutes
During heating operation, at the time point when TO supplement-TL2 ≥ 5K is continued
for 5 minutes
• The header outdoor unit will be stopped, and the system restart prevention timer will
be set.
• For the follower outdoor units, the compressor of the unit that detected the abnormality
is turned off to prevent the compressor from restarting.
Set the timer and send the [compressor start permission: OFF] signal outside the
center room.
• Abnormality count is [1].
<Other points to note>
1) Cooling Operation at Low Outdoor Temperature
① When suction pressure (Ps) decreases, the indoor unit operation may stop due to anti-frost control based
on the temperature of the TC sensor of indoor unit.
② When suction pressure (Ps) decreases, the compressor speed [rps] may be decreased due to cooling capacity control.
③ When discharge temperature (TD) is lower than 140.0°F(60°C),the compressor speed [rps] may be increased due to
indoor unit command.
2) PMV (Pulse motor Valve)
① When power is turned on, the PMV will initialize and make a knocking sound. If there is no knocking sound,
there is possibility of PMV malfunction. However, if the outdoor unit area has high ambient noise, there is possibility PMV
knocking sound may not be heard.
② Do not remove PMV Coil (head part) during operation. It will affect the control valve opening.
③ When transporting the set, do not ever remove the PMV Coil. Valve will close and sealing the liquid refrigerant
which may damage the valve.
④ When removing and reattaching the PMV Coil, push in the coil firmly until [Click] sound is heard, turn off the power
and turn it on again.
3) Fan mode during heating operation on same system line of indoor unit
In the same system line of indoor unit, if there's one indoor unit is on the heating operation, the other indoor units cannot do
Fan Mode. The indoor unit for which Fan Mode is selected will be forcibly stopped, and [ "operation standby
displayed on the remote controller. Refrigerant will accumulate in the indoor unit that is operating in fan mode. This condition
is set to prevent repeated refrigerant recovery.
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Remarks
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