TemperZone UC8 User manual

Temperzone UC8 Troubleshooting Guide
Page 1 of 24
UNIT CONTROLLER 8 (UC8)
Troubleshooting guide
Date: 21 April 2017
Issue: 3

Temperzone UC8 Troubleshooting Guide
Page 2 of 24
Contents
1. Cautions........................................................................................................................................... 3
2. Recommended service tool set ........................................................................................................ 3
3. Recommended set of spare parts ..................................................................................................... 3
4. Items to check first........................................................................................................................... 3
5. Controller start-up procedure........................................................................................................... 4
6. Viewing system information ........................................................................................................... 5
7. Controller test mode ........................................................................................................................ 6
8. Commissioning mode...................................................................................................................... 7
9. Timer durations................................................................................................................................ 7
10. Troubleshooting procedure.............................................................................................................. 8
11. Fault messages............................................................................................................................... 10
12. Fault codes..................................................................................................................................... 13
13. Inverter fault codes........................................................................................................................ 16
14. Fault codes shown on a room thermostat ...................................................................................... 17
TZT-100 room thermostat fault codes ................................................................................. 17
SAT-3 room thermostat fault codes..................................................................................... 17
SAT-3 internal fault codes ................................................................................................... 17
SAT-3 + Zone controller fault codes ................................................................................... 17
SAT-3 + UC8 fault codes..................................................................................................... 18
15. Protection function details............................................................................................................. 19
High pressure protection (HP).............................................................................................. 19
Low pressure protection (LP)............................................................................................... 19
Indoor coil frost protection................................................................................................... 19
High temperature protection................................................................................................. 19
High suction line / evaporating temperature protection....................................................... 20
Low discharge side superheat protection............................................................................. 20
High discharge side superheat protection............................................................................. 20
Freeze protection.................................................................................................................. 20
Reverse cycle valve fault protection .................................................................................... 21
Overload protection.............................................................................................................. 21
High compression ratio protection....................................................................................... 21
Low compression ratio protection........................................................................................ 22
16. Lock-out......................................................................................................................................... 22
17. Unit log.......................................................................................................................................... 23

Temperzone UC8 Troubleshooting Guide
Page 3 of 24
1. Cautions
 Turn off mains power before opening the electrical panel of a unit.
 When disconnecting and connecting connectors hold them by the housing. Do not pull on the
wires.
 Use as little force as possible when replacing electronic circuit boards.
 Never pull on individual electronic components.
2. Recommended service tool set
Set of screwdrivers of various sizes: blades, pozi-drive and Phillips
Socket set (6mm to 19mm metric)
Allan keys (5mm to 10mm metric)
Small and medium size crescent
Long nose pliers
Multi-meter and probe leads of good quality
Bottle with R410a refrigerant
Refrigerant scales
Mobile telephone / Smart-phone
Additional potentially useful items:
Amp-meter clamp
Temperature probe
Length of appliance wire, mains voltage rated
Wire cutting and stripping tool
Roll of electrical insulation tape
Quick-connect (spade) terminals (6.3mm, 0.25”) (plastic or rubber insulating boots are useful too)
Quick-connect (spade) crimp tool
Pressure gauges for R410a refrigerant
Torch or other battery powered lamp (e.g. headlamp)
Temperzone wireless service tool (WSU) and a smart phone
Laptop computer with USB to RS485 converter (Hyperterm or TeraTerm program installed)
3. Recommended set of spare parts
Known good UC8 controller circuit board, programmed with software version 2.1.9 or later
Set of Temperzone standard temperature sensors (yellow, blue, red and white leads)
34.5 bar and 45 bar pressure transducers
Temperzone pressure transducer leads
4. Items to check first
What exactly is the complaint? Does the unit run at all?
Under which conditions does the problem occur?
Check mains power is properly connected and is the mains voltage correct.
Check control wires between indoor and outdoor units and to the thermostat or other controller.
Check all unit internal wiring is securely fastened and connected.
Check that DIP switch settings agree with information given in the unit documentation.
Take careful note of any information shown on the controller board display.

Temperzone UC8 Troubleshooting Guide
Page 4 of 24
5. Controller start-up procedure
When mains power to the UC8 controller is switched on it follows a defined start-up procedure. The
controller start-up procedure is, in this order:
1. The yellow light marked Power must illuminate.
2. The display must show the characters UC8 (one character at a time).
3. The display must show the software version as three numbers with two dots (decimal points)
in between. Example: 2.1.9
4. If the unit was locked out due to repeated trips, then it will next show the cause of the most
recent lock-out. Note this is not a fault! The message will be shown for about half a minute
after which the controller will continue the normal start-up sequence. This message will no
longer be shown after the unit has completed at least one normal cooling or heating cycle.
5. The display will show the type/model of the compressor it is configured for. Refer to the table
below for a list of available compressors.
6. A controller configured as a master (DIP switches 11 and 12 both OFF) will show the message
dELAY, for between 10 to 20 seconds.
Air-to-air units only: A controller configured as a slave (one or both DIP switches 11 and 12
ON) will show the message ctrL, until the master controller has made contact with the slave.
7. The display must show a flashing decimal point (a dot). The flashing dot indicates the unit has
commenced normal operation and no faults are reported.
List of available compressors:
Compressor
Drive
UC8 display
indication
DIP switch 2
setting
Fixed capacity
Not required
dF
Off
Digital scroll
On
Copeland ZPV038
Carel Power+ PSD1024400
038
-
Toshiba DA550
Carel Power+ PSD1018400
Or PSD1024400
550
Siam ANB66
Carel Power+ PSD1024400
66
-
Siam ANB78
Carel Power+ PSD1024400
Or PSD1035420
78
-
Siam ANB87
Carel Power+ PSD1035420
87
-
Copeland ZPV063
Emerson CSD100
063
-
Other inverter
Type with 0-10V input
010
-

Temperzone UC8 Troubleshooting Guide
Page 5 of 24
6. Viewing system information
When the controller is operating normally the display will show a flashing dot or, if operating in
commissioning mode, a flashing letter c. Under those conditions it is possible to use the display on the
UC8 controller to view information on pressures, temperatures, superheat, expansion valve opening,
capacity and the controller Modbus address. This is available regardless whether the compressor is on
or off. It is not available when the controller is reporting a fault.
To view system information:
Repeatedly press the pushbutton to cycle the display through the options (in a round robin fashion).
-Temperatures are shown in degrees Celsius (°C). If the indicated temperature is below 0°C then a
minus sign is shown before the value. If the unit has one or two pressure transducers then the
condensing and/or evaporating temperatures shown are converted from pressure readings.
-Pressures are shown in kPa. Divide by 6.895 (roughly 7) to convert to PSI.
-If a sensor reading is not available then the display shows a dash, for example: SLP –
-If the unit does not have electronic expansion valves then it shows value 0; example: EE1 0
-After 2 minutes the display automatically returns to a flashing dot (or c).
Display
Meaning
Units
● or c
Normal mode (default)
SLP
Compressor suction line pressure
kPa
Et
Evaporating temperature
°C
SLt
Compressor suction line temperature
°C
SSH
Suction side superheat
K
dLP
Compressor discharge line pressure
kPa
Ct
Condensing temperature
°C
dLt
Compressor discharge line temperature
°C
dSH
Discharge side superheat
K
ICEt
Outdoor coil de-ice sensor temperature
°C
CAP
Unit capacity (duty)
%
EE1
Expansion valve 1 opening
%
EE2
Expansion valve 2 opening
%
Add
Controller Modbus address
-

Temperzone UC8 Troubleshooting Guide
Page 6 of 24
7. Controller test mode
A controller test mode is available that can provide a quick check of the operation of relays, contactors
and fans. Test mode can only be activated when the unit is not already in commissioning mode, the
compressor must be off and the thermostat or BMS must not request to start.
To activate test mode hold down pushbutton SW3 until the display shows the letter ‘t’, then release the
button.
During test mode following outputs are activated one by one, in the order indicated in the table below,
with a brief pause between each step. When the test sequence is complete the UC8 returns to normal
mode and the display will show the suction line pressure (letters SLP followed by the pressure in kPa)
or it may return to show a flashing decimal point.
Step
Test
Duration (seconds)
Notes
1
Output R/V (reverse-cycle valve)
2
2
Outdoor fan low speed
7
1, 3, 4, 5
3
Outdoor fan medium speed
7
4
Outdoor fan high speed
15
5
Indoor fan low speed
7
2, 3, 6, 7, 8
6
Indoor fan medium speed
7
7
Indoor fan high speed
15
8
Output SSR1
2
9
Output SSR2
2
10
Output AUX
2
11
Pressure transducer test
1
9
12
Output CMC (compressor contactor)
2
Notes:
1Steps 2, 3 and 4 are skipped on hydronic units (no outdoor fan).
2Steps 5, 6 and 7 are skipped on chillers and water-heating units (no indoor fan).
3If the fan is a three speed type then relays Low, Medium and High activate in turn.
4If the outdoor fan is a variable speed type (0-10V control) then relay Medium will activate, but
only if this relay is not required for a three-speed indoor fan.
5If the outdoor fan is a single-speed type then relay Medium activates for 29 seconds in total.
6If the indoor fan is a variable speed type (0-10V control) then relay High will activate, but only
if this relay is not required for a three-speed outdoor fan.
7If the indoor fan is a single-speed type then relay High activates for 29 seconds in total.
8If the unit is a split type and the indoor unit has an indoor unit controller (IUC) then the indoor
fan is tested via the IUC and steps 5, 6 and 7 will not activate any output on the UC8 controller.
9Step 11 is skipped if the unit does not have both the low- and the high-pressure transducers. If
the test is performed then pressure readings are expected to be approximately equal. If they are
found to be very different then fault F34 is reported. The fault is cleared automatically when
pressures are sufficiently equalised.

Temperzone UC8 Troubleshooting Guide
Page 7 of 24
8. Commissioning mode
A controller commissioning mode is available that allows doing a quick check of the operation of the
entire unit. Commissioning mode can only be activated when the compressor is off and the thermostat
or BMS must not request to start.
To activate commissioning mode hold down pushbutton SW3 until the display shows the letter ‘c’, then
release the button.
Commissioning mode starts immediately and ends automatically after 30 minutes. It is also possible to
manually end commissioning mode either by cycling mains power off and on again, or by pressing the
pushbutton again until the display again shows the letter ‘c’ and then release. When commissioning
mode ends the controller returns to normal operating mode.
During commissioning mode some delay times are reduced:
Minimum On-Off time (‘Run’-time) 20 seconds (note)
Minimum Off-On time (‘Off’-time) 20 seconds
Minimum On-On time (‘Cycle’-time) 1 minute
Cool to heat change-over time 1 minute
Heat to cool change-over time 1 minute
De-ice mode hold-off time 3 minutes
Note:
If the unit has a variable speed compressor then the Minimum On-Off time (‘Run’-time) remains set to
90 seconds regardless whether the controller is placed in commissioning mode or not.
9. Timer durations
Safety timer
Duration
Unit start-up delay (after mains power-on)
2 minutes
Minimum compressor run-time
(On-to-Off duration)
90 seconds
Minimum compressor off-time
(Off-to-On duration)
3 minutes
Minimum compressor cycle-time
(On-to-On duration)
6 minutes
(a maximum of ten compressor starts per hour)
Hydronic unit compressor start delay
(allows time for a water valve to open)
45 seconds
HP protection
3 minutes
LP protection
3 minutes
Compressor high discharge pipe temperature
protection
3 minutes
Indoor coil frost protection
6 minutes
Hydronic unit water freeze protection
3 minutes
High suction line temperature/pressure
protection
3 minutes
Low / high discharge superheat protection
3 minutes
Overload protection
3 minutes
High / low compression ratio protection
3 minutes

Temperzone UC8 Troubleshooting Guide
Page 8 of 24
10. Troubleshooting procedure
Check:
1. Mains power is supplied to the unit.
2. The main isolating switch and the control circuit
breaker are on.
3. All mains wiring and connectors are OK.
4. Mains phases connect in the right sequence.
5. 230V AC voltage is present across the UC8 L and N
terminals.
6. No short circuit exists between UC8 terminals 12 and
0V.
No
Yes
No
Yes
The UC8 and/or IUC remote On/Off input is/are open
circuit.
No
Yes
A compressor safety timer is active.
Wait until the timer expires.
Power light is
on?
Display shows
flashing dash
▬?
Display shows
HOLd and a
number?
Check:
1. Check power is switched on to the compressor driver
(inverter).
2. Check the connections between the UC8 and the
compressor driver.
3. Check the DIP switches inside the compressor driver
agree with the instructions on the wiring diagram.
Display shows
code F100?
No
Yes
Display shows
code ctrL?
No
Yes
Is this a slave
unit?
No
Yes
Check:
1. Mains power to this slave-
controller was applied at the
same time (or before) as to the
master-controller.
2. Connections between the
master and the controllers.
3. No short circuit exists between
terminals A1 and B1 (slave-
controller) or between A2 and
B2 (master unit).
Check:
DIP switches 11 and 12 are
both set to OFF. Correct if
necessary, then cycle mains
power off and on again.
Continued next page.
Unit does not run

Temperzone UC8 Troubleshooting Guide
Page 9 of 24
No
Yes
No
Yes
DRED energy restriction is active:
Wait until DRED energy restriction condition ends.
If DRED function is not required:
Air-to-air units: Inputs D1, D2, D3 should be open
circuit (Note: Inputs D1 and D2 may be used to
control Quiet and Dry modes.)
Hydronic units: Input D3 should be open circuit.
Chillers: Inputs D1, D2, D3 should be open circuit
Display shows a
flashing dot ●?
Display shows dr?
Display shows a
code listed in
chapters 11, 12
or 13?
The controller has detected a fault.
Refer to chapters 11, 12 and 13.
Yes
es
No
Contact Temperzone customer service.
Check wiring between UC8 and
the thermostat.
Continued from previous page.
Satellite dish shown
on t-stat display?
Yes
No
TZT-100 or SAT-3
wall thermostat?
No
Yes
Display shows
diFF-P?
Pressure differential is too high to allow the inverter
compressor to start:
Wait until the pressures have equalised.
Ensure valves are open.
Ensure the EEV operates correctly.
Yes
es
No
Correct
compressor
model selected?
Change the compressor model selection.
Yes
es
No

Temperzone UC8 Troubleshooting Guide
Page 10 of 24
11. Fault messages
Display
Meaning
Possible causes
Possible remedy
LP
Low pressure
protection
Check for refrigerant leaks.
Fix leak, evacuate unit, then recharge.
Expansion valve (EEV) is
closed.
Check valve coil is properly fitted onto the valve
body.
Check UC8 DIP switch settings.
Repair wiring to the valve.
Replace expansion valve.
Faulty transducer cable.
Faulty transducer.
Faulty LP switch.
Repair transducer cable.
Replace transducer.
Replace LP switch.
Service valve is closed.
Open service valves.
Indoor fan does not start
(cooling mode) or
outdoor fan does not start
(heating mode).
Repair fan wiring.
Replace fan.
Incorrect DIP switch settings.
Change DIP switch settings then restart the
controller.
HP
High pressure
protection
Outdoor fan does not start
(cooling mode) or
indoor fan does not start
(heating mode).
Repair fan wiring.
Replace fan.
Unit is overcharged.
Remove excess refrigerant charge.
EEV is closed.
Check UC8 DIP switch settings.
Repair wiring to the expansion valve.
Replace expansion valve.
Faulty transducer cable.
Faulty transducer.
Faulty HP switch.
Repair cable to the transducer.
Replace transducer.
Replace HP switch.
Service valve is closed.
Open service valves.
Incorrect DIP switch settings.
Change DIP switch settings then restart the
controller.
HI-t
High
temperature
protection
Insufficient refrigerant.
Add refrigerant.
Faulty discharge line
temperature sensor.
Replace sensor.
Incorrect DIP switch settings.
Change DIP switch settings then restart the
controller.
FROSt
Indoor coil
frost
protection
Air filter blocked.
Clean or replace air filter.
Dampers closed.
Check dampers and damper controls.
Excess amount of cold fresh
air introduced.
Check fresh air damper and damper controls.
Indoor fan speed too low.
Increase indoor fan speed.
Faulty indoor fan motor.
Faulty indoor fan speed
controller.
Replace indoor fan motor.
Replace indoor fan speed controller.
Return air temperature too
low.
Ensure unit is not operated in cooling mode
with very low return air temperature.
Insufficient refrigerant.
Add refrigerant.