Refrigerant Amount Adjust Mode PowerPoint

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Refrigerant Amount Adjust Mode
TGMU, THMU, TJMU and TKMU
CITY MULTI
Refrigerant Amount
Adjust Mode is
described in the
Technical Service
Manual in the form of a
troubleshooting tree
diagram.
This presentation will
use this tree and MTool to facilitate this
operation.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 2
 Adjusting Charge
starts differently
based on outdoor
unit generation.
 TGMU starts with
Outdoor dip switch
2-4 ON
 THMU/TJMU starts
with Outdoor dip
switch 4-3 ON
(OC only).
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 3
Adjusted Charge on TKMU starts when the
function switch SW4 (922) on the main board of
the OC only is turned ON. This can be
accomplished in one of two ways.
The first method can be initiated by using OC dip
switches.
On the main board of the outdoor unit turn ON
SW6-10 then dip switches SW4-2,4,5,8,9,10 ON.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 4
At this point 922 should
be displayed on LED 1 of
the outdoor main board.
Next press and hold
SWP-1 for 2 seconds or
longer, LED 3 will light
confirming selected
function.
TKMU
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 5
There’s a easier way to initiate function 922 on
TKMU’s, by using M-Tool! This method is much
easier and allows adjusted charge to be initiated
and performed from your computer.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 6
From the
address grid
select OC
then
Optional Set
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 7
Confirm the
OC address
is correct
then select
OC
Function
Setting.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 8
From this
screen select
922 ON, then
select Set.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 9
Put all indoor units in
Test Run and Cool
Mode. This will allow
the indoors units to
operate for a two hour
period. The set point
does not require
changing, as it will be
ignored during Test
Run.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 10
Be sure the Ctrl Mode
of the outdoor unit or
units is Ordinary.
Be sure it has been at
least 30 minutes since
system startup.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 11
Here we can
confirm that the
Ctrl Mode is in
Ordinary and
all indoor units
are in Test Run
Cool Mode.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 12
Is discharge gas
temperature TH4 less
than 212 ºF?
If not then gradually
add liquid refrigerant
to the low pressure
service port until TH4
is less than 212 ºF.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 13
Remember discharge gas temperature on TGMU
generation is TH11.
All others THMU, TJMU and TKMU discharge gas
temperature is TH4.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 14
TH4 must be less
than 212 ºF
before continuing.
After adding
refrigerant wait at
least 5 minutes to
allow system to
adjust.
Weight the charge and
record the amount!
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 15
Once TH4 is less than
212 ºF be sure the
compressor
frequencies of the OC
and OS are stable
before continuing to
the next step.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 16
“Stable
frequency,”
means there will
be no hunting.
The frequencies
will lock into a
specific range.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 17
Is the superheat (SH)
equal to or greater
than 9 ºF?
If no be sure the
position of the LEV’s
are stable.
The SH of all indoor
units should be
between 9 ºF and 27
ºF before continuing
to the next step.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 18
The pulse position
of the LEV’s (Li)
will stabilize and
SH should be
between 9 ºF and
27 ºF.
Remember if there is a
malfunctioning LEV
causing a indoor unit to
flood, SH will be low and
system data may mimic
low charge!
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 19
 SC1 is the sub
cooling of the first
heat exchanger in the
BC. It should be
between 9 ºF and 27
ºF.
If not, gradually add
liquid refrigerant to
the low pressure
service port.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 20
Remember to allow at least 5 minutes for the system
to adjust after adding refrigerant. This will help
ensure you do not overcharge!
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 21
SC6 is the sub
cooling on the
second heat
exchanger in the
BC. It should be 27
ºF or greater.
If not, gradually add
liquid refrigerant to
the low pressure
service port.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 23
Is discharge gas
temperature TH4
on the OC and OS
below 203 ºF?
If not gradually add
refrigerant until
TH4 is less than
203 ºF.
If yes then adjusted
charge is complete.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 25
Turn off dip
switches that
initiated Refrigerant
Amount Adjust
Mode.
If you used M-Tool
to start function 922
it will be necessary
to Stop indoor unit
operation before
turning off 922 via
M-Tool.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 26
Cooling only mode is uses for
adjusting charge because there
is a specific amount of sub
cooling required on the two
tube in tube heat exchangers in
the Branch Controller (BC).
The nomenclature identifying
temperature sensors and sub
cooling will change from
manuals to M-Tool.
TH11 = TH1
SC11 = SC1
TH12 = TH2
SC16 = SC6
TH15 = TH5
TH16 = TH6
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 27
Sub cooling on the first tube in
tube heat exchanger (SC1) is
calculated using PS1 (pressure
sensor) and TH11 (temperature
sensor).
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 28
Sub cooling on the second tube
in tube heat exchanger (SC6) is
calculated using PS3 (pressure
sensor)and TH16 (temperature
sensor).
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 30
The heat exchanger superheat
(SH2) is calculated using
temperature sensors TH15 and
TH12.
© 2012 Mitsubishi Electric & Electronics USA, Inc.
Slide 32
Thank You!

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