Mitsubishi problem

[mattltm]

Hi All,

We have a large multi-city install with 3 x 2 banks of units on the roof, about 90 internal units split over 50 offices and 3 floors controlled via 3 x g50 controllers.

We currently have no heating and can not get hold of out engineers!

The local controllers in the offices are giving a variety of codes including 7100 and 7102. The G50's are showing no errors!

Can someone point me in the right direction to get things running again?

Thanks.

[stufus]

Hey Matt
7100 ,7101,7102 are all capacity errors, meaning the outdoor units detect either too many indoor units connected or no indoor units connected, a power reset at the outdoor unit usually clears this up providing you have power at all indoors and bc's . If not check transmission line voltage and capacity setting setting on outdoor board sw2 if memory serves me correctlly.. best of luck !!

Stu

[stufus]

Matt its actually SW3-10 for outdoor unit capacity.
SW2 is capacity for the indoor units and is listed on the indoor electrical cover.selector
switch (SW3-10).
1) The Indoor unit model name (model
code) connected is not connectable.
Connectable range.....20~250
2) Erroneous setting of the switch
(SW2) for setting of model name of
Indoor unit connected.
1) Number of unit connected to terminal
block (TB3) for outdoor/indoor
transmission line exceeds limitations
given be-lows:
Item Limitation
Total of 200:1~13
Indoor unit 250:1~16
Total of Indoor
unit & RC 1~35
(3) System error
Checking
code
7100
7101
7102
Meaning, detecting method Cause Checking method & Countermeasure
Total capacity error
Total capacity of indoor units in
the same refrigerant system exceeds
limitations.
Trouble source:
Outdoor unit
Capacity code error
Error display at erroneous connection
of Indoor unit of which
model name can not be connected.
Trouble source :
Outdoor unit
Indoor unit
Connected unit count over
Number of units connected in the
same refrigerant system exceeds
limitations.
Trouble source:
Outdoor unit
a) Check for the model total (capacity cord total) of
indoor units connected.
b) Check whether indoor unit capacity code (SW2)
is wrongly set.
For erroneous switch setting, modify it, turn off
power source of outdoor unit, and indoor unit
simultaneously for 5 minutes or more to modify
the switch for setting the model name (capacity
coad).
Check for the model selector switch (Dip switches
SW3-10 on outdoor unit control circuit) of OC.
a) Check for the model name of the Indoor unit
connected.
b) Check for the switch (SW2 if indoor controller
for setting of Indoor unit model name of generating
address. When it is not agreed to the model
name, modify the capacity code while shutting
off the power source of Indoor unit.
❇ The capacity of Indoor unit can be confirmed by
the self-diagnosios function (SW1 operation) of
Indoor unit.
a) Check whether the connection of units to the
terminal block for indoor/outdoor transmission
wiring (TB3) of outdoor unit is not exceeding the
limitation.
b) Check for 2), 3), and 4).
c) Check for the connection of transmission wiring
to the terminal block for centralized control is
erroneously connected to the indoor/outdoor
transmission wiring terminal block (TB3).
Model Total capacity code
200 53
250 66
1
ON 250
OFF 200
2 3 4 5
SW3
6 7 8 9 10
.....

[Thermatech]

1st Try a re set by going to each G50 & switch off all indoor units.
Then switch all indoor units back on.

If problems continue
Carry out a full system reset. For this you need to turn off electrical power to all indoor units & outdoor units.
1/ Turn off all indoor units at the G50 central controllers.
2/ Find the power distribution board which serves the outdoor units & turn off the 3 phase power to all the outdoor units.
3/ Find the power distribution board on each floor & turn off the ring main circuits to all the indoor units. Leave switched off for a few mins & then turn back on.
4/ Go back & turn on the 3 phase power to all the indoor units.
5/ After 5 mins go to each G50 & turn all indoor units back on.

If the faults are only with one system & G50 then only do the full power reset to that G50 & indoor units / outdoor unit on that floor.

If your building is very cold inside it may take quite a few hours to gradually warm up even with all systems fully operational & outdoor units running flat out.
With this extreem cold weather I would recomend leave to operate 24/7 untill the cold weather passes.

Any further problem will need the maintenance contractor to attend site & investigate.
Most contractors are flat out busy due to the extreem weather at the moment.

[mattltm]

Thanks all for your advice and help.

The fault turned out to be a dead unit on the roof. We replaced the noise filter PCB and all is now working fine.

Thanks for the help.

[JoeAT50A]

Thanks mattltm, in general noise filter cases are belong to error codes 4xxx but your case is 7xxx.
Stufus's approach is better because we normally 7xxx are more relate to either capactiy or Mnet.
However we noted your resolution.

[install monkey]

4 1/2 months to rectify-not bad

[JoeAT50A]

4 1/2 months to rectify-not bad

Don't worried RE forum is active, he could be here sooner, most worse cases 4 1/2 days or some 4 1/2 hrs I beleived. Don't you agree?? Hey Stufus, support me...

[stufus]

All's well that ends well .
Better late than never
Cheers
Stu