UNITED C5 Series Supplement

End User Disclaimer
1
End User Disclaimer:
United systems have absolutely no end user serviceable
parts. United does not authorize attempts by the spa owner/
user to install or repair/service any United products.
Non-qualified users should never open or remove covers, as this will
expose dangerous voltage points and other serious risks.
Non-qualified users should not attempt to make changes to the topside’s
programming, as mis-programming can result in malfunction or possible
damage.
Please contact your dealer or a locally licensed service center for service
and technical support.
This installation and service manual is provided solely to aid qualified spa
service technicians in installing, setting up, and troubleshooting spas with
United systems.

Table of Contents
2
End User Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Electrical Installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
120V Cord and Plug Connected . . . . . . . . . . . . . . . . . . 3
120V Permanently Connected . . . . . . . . . . . . . . . . . . . 4
240V Installation - 4-Wire . . . . . . . . . . . . . . . . . . . . . . . 5
240V Installation - 3-Wire (No Neutral) . . . . . . . . . . . . . 6
Control Box Installation . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Finishing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Important Troubleshooting Information . . . . . . . . . . . . 10
Incoming Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Troubleshooting Test Points . . . . . . . . . . . . . . . . . . . . 13
Transformer & 2A Glass Fuse . . . . . . . . . . . . . . . . . . . 14
Low Voltage Circuit & Light Circuit . . . . . . . . . . . . . . . 15
Pumps/Blower/Ozone . . . . . . . . . . . . . . . . . . . . . . . . . 16
Heating Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Replacing Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
C5 Series Specs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Electrical Installations
3
120V Installation (Cord and Plug Connected Units):
Equipment Modules provided with a factory installed power cord are to be
plugged into a grounding type, 120 volt, receptacle.
The connection of the plug to a 240 volt service will cause the Equipment
Module to operate improperly, create the potential for an electrical hazard,
and will void the warranty.
The electrical supply for cord and plug connected units must include a
suitably rated Ground Fault Circuit Interrupter (GFCI) in compliance with
Article 680-42 of the National Electrical Code. ANSI/NFP70. No other
electrical appliance or fixture should be used on this circuit.
• Use only dedicated electrical line with 20 amp breaker.
• Do not use an extension cord.
• Always use a weatherproof covered receptacle.
• Do not bury the power cord.
Weather Proof GFCI Kit
Weatherproof Receptacle Cover
Spa Power Cord 120V GFCI
Back View
Incoming Power from Main Panel (Black) Incoming Neutral from Main Panel (White)
Ground
LOAD
LINE

Electrical Installations
4
120V Installation (Permanently Connected Units):
Units to be operated at 120 volt must have all electrical connections
accomplished by a qualified electrician in accordance with the National
Electrical Code or the Canadian Electrical Code, and other electrical
codes at the time of installation. All connections must be made with
copper conductors. The conductors and circuit breaker must be sized to
accommodate the total amperage load as specified on the Equipment
Module data label. Equipment Modules installed for 120 volt operation
require a two wire electrical service, plus ground. Line 1 (black), Neutral
(white), and Ground (green).
The disconnecting means must be readily accessible to the tub occupant
but installed at least 5 feet (1.5 m) from tub water. The electrical supply
for permanently connected units must include a suitably rated Ground
Fault Circuit Interrupter (GFCI) in compliance with Article 680-42 of the
National Electrical Code. ANSI/NFP70. No other electrical appliance or
fixture should be used on this circuit.
Weather Proof GFCI Kit
Weatherproof Receptacle Cover
120V GFCI
Back View
Power from
Main Panel
(Black)
Neutral from
Main Panel
(White)
Ground
LOAD
LINE
Neutral to Spa (White) Power to Spa (White)

Electrical Installations
5
240V Installation (4 wire - Line 1, Line 2, Neutral, and Ground):
Units to be operated at 240 volt must have all electrical connections
accomplished by a qualified electrician in accordance with the National
Electrical Code or the Canadian Electrical Code, and other electrical
codes at the time of installation. All connections must be made with
copper conductors. The conductors and circuit breaker must be sized to
accommodate the total amperage load as specified on the Equipment
Module data label. Equipment Modules installed for 240 volt operation
require a three wire electrical service, plus ground. Line 1 (black), Line 2
(red), Neutral (white), and Ground (green).
The disconnecting means must be readily accessible to the tub occupant
but installed at least 5 feet (1.5 m) from tub water. The electrical supply
for permanently connected units must include a suitably rated Ground
Fault Circuit Interrupter (GFCI) in compliance with Article 680-42 of the
National Electrical Code. ANSI/NFP70. No other electrical appliance or
fixture should be used on this circuit.
Cuttler Hammer Spa GFCI Breaker Panel
Breaker
Enclosure
Neutral Bar
Neutral Pigtail
Ground Bar
Ground from Main Panel
Power from Main Panel
Neutral from Main Panel
Power from Main Panel
Power to Spa
Neutral to Spa
Power to Spa
Ground to Spa
GFCI Breaker
Bottom View of GFCI
Power to Spa
Neutral to Spa
Hard Wired Neutral
to Neutral Bar

Electrical Installations
6
240V Installation (3 wire - Line 1, Line 2, and Ground):
Units to be operated at 240 volt must have all electrical connections
accomplished by a qualified electrician in accordance with the National
Electrical Code or the Canadian Electrical Code, and other electrical
codes at the time of installation. All connections must be made with
copper conductors. The conductors and circuit breaker must be sized to
accommodate the total amperage load as specified on the Equipment
Module data label. Equipment Modules installed for 240 volt operation
require a two wire electrical service, plus ground. Line 1 (black), Line 2
(red), and Ground (green).
The disconnecting means must be readily accessible to the tub occupant
but installed at least 5 feet (1.5 m) from tub water. The electrical supply
for permanently connected units must include a suitably rated Ground
Fault Circuit Interrupter (GFCI) in compliance with Article 680-42 of the
National Electrical Code. ANSI/NFP70. No other electrical appliance or
fixture should be used on this circuit.
Cuttler Hammer Spa GFCI Breaker Panel
Breaker
Enclosure
Neutral Bar
Neutral Pigtail
Ground Bar
Ground from Main Panel
Power from Main Panel
Neutral from Main Panel
Power from Main Panel
Power to Spa
Power to Spa
Ground to Spa
GFCI Breaker
Bottom View of GFCI
Power to Spa
Hard Wired Neutral
to Neutral Bar

Control Box Installation
7
Mounting and Plumbing Considerations
The C5 control box is made for above ground portable hot tubs. As such
it is an indoor unit, meant to be mounted inside of the portable hot tub’s
enclosure. Water may flow through the heater in either direction, as long
as the water is being pushed through it (plumbed up to the discharge of
the pump). Plumbing the heater up to the suction of the pump will not allow
the heater to operate.
Temperature Sensor Installation
The C5 control box comes with a 1/4” diameter temperature sensor. This
is a dry sensor that is not to be exposed to water. Its probe is meant to be
installed into a thermowell which itself should be installed mid-water level
in the hot tub to provide the most accurate temperature reading. After
installing the temperature sensor probe, be sure to plug the connector on
the end of the cable into the temperature sensor receptacle on the control
box. The included sensor is carefully calibrated to it’s cable’s length, and
therefore must in no way be altered or shortened/lengthened.
Equipment Connection
The Circulation Pump receptacle is for circulation pumps (rated 2A or
less). If your pump does not match this description it must be connected to
the Pump-1 receptacle and used as Pump-1. See page 11 for an important
note on how to wire the Circulation Pump cord for timed operation!
The C5 control uses the red wire for low-speed operation of Pump-1 and
Pump-2. Connecting a single speed pump as Pump-1 for both operating
the jets and heating/filtration is not recommended, but if you must use a
single speed pump for both, you must connect the red and black wires of
the pump cable together up to the high speed terminal on the back of the
pump’s motor to both operate jets and heat/filter.
If you are connecting an air blower or third pump to the Auxiliary
receptacle, then if there is a two speed Pump-2 it must be wired for single
speed (no red wire) operation at the back of the motor.

Control Box Installation
8
The Pump-1 and Pump-2 receptacles
are pre-wired for 240V. The Ozone,
Circulation Pump, Auxiliary, Audio,
and Gas (on the C5-G) receptacles are
all pre-wired for 120V.
These receptacles are all dyed different
colors, and have white wires striped
with their respective receptacle’s color.
To change the voltage of a receptacle
simply move it’s correspondingly color
striped white wire at the power lugs from
Neutral to Line 2 to convert to 240V, or
from Line 2 to Neutral to convert to 120V.
The Light receptacle is pre-wired for industry standard 12V lighting, up to
0.9A. To convert the receptacle
to operate 120V lighting (up to
2A) the two jumper wires on
the circuit board marked ‘SPA
LIGHT’ must be moved from
‘Low V’ to ‘High V’. Both wires
must be moved together, as
shown in the diagrams. Wiring
the jumper wires in any other
configuration then shown in the diagrams may damage the circuit board!
Power Installation
For 4-wire 240V power installations
the incoming Line-1, Line-2, and
Neutral wires will need to be connected
to the correspondingly labeled power
lugs on the circuit board. The ground
wire will need to be connected to the
ground lug fastened to the aluminum
frame right next to the board.
NEUTRAL
LINE-2
LINE-1
SPA LIGHT
HI V
LO V
SPA LIGHT
HI V
LO V
12V Light
(Default)
120V Light
Place wire on
Neutral to make
receptacle 120V
Place wire on
Line-2 to make
receptacle 240V
NEUTRAL
LINE-2
LINE-1

Control Box Installation
9
For 3-wire 240V power installations
the incoming Line-1 and Line-2 wires
will need to be connected to the
correspondingly labeled power lugs on
the circuit board. The incoming Line-2
will also need to be brought to the
Neutral power lug. The ground wire will
need to be connected to the ground lug
fastened to the aluminum frame right
next to the board.
For 120V power installations the
240V transformer will need to be
swapped out with it’s 120V equivalent.
The incoming Line-1 and Neutral
wires will need to be connected to the
correspondingly labeled power lugs on
the circuit board. The incoming Neutral
will also need to be brought to the
Line-2 power lug on the circuit board.
Finishing Installation
After installation of the C5 control box is complete, its time to read through
the installation manual and user’s guide booklet that comes packaged with
the topside control. The installation manual will guid you through installing
and programming the topside which completes the installation process.
NEUTRAL
LINE-2
LINE-1
NEUTRAL
LINE-2
LINE-1

Troubleshooting
10
Important Troubleshooting Information
When troubleshooting a United Spas control system, no matter how minor
the issue is, the first things that must be checked are the incoming power
to the control board and the output power of the transformer.
You will need to set your multi-meter or voltmeter for AC Volts when testing
voltages within the United Spas control system. You will only set your
multi-meter or voltmeter to DC Volts when testing the IC Regulator Chip.
Once you’ve completed the incoming voltage and transformer voltage
checks as outlined on the next few pages, you can proceed with further
diagnosis using the test points and instructions outlined later in this section.
Warning:
When working on the control box be aware that it may
contain high voltage wiring.
Warning:
Always keep your fingers and tools away from the circuit
board and any wiring while the power is on. Serious injury
may result!
Warning:
Make sure that the power to the control box is shut off
before touching any wiring.

Troubleshooting
11
Incoming Voltage Checks
Voltage Check for 120V Incoming Power:
120VAC (Range of acceptability: 108VAC to 132VAC) should be read
between; Neutral and Line-1, Line-2 and Neutral, and Line-1 and Ground.
Voltage Check for 240V (3-Wire) Incoming Power
240VAC (Range of acceptability: 216VAC to 264VAC) should be read
between Line-2 and Line-1, and between Neutral and Line-1.
NEUTRAL
LINE-2
LINE-1
NEUTRAL
LINE-2
LINE-1
Neutral and Line-1
240VAC (216VAC-264VAC)
Line-2 and Line-1
240VAC (216VAC-264VAC)
NEUTRAL
LINE-2
LINE-1
NEUTRAL
LINE-2
LINE-1
NEUTRAL
LINE-2
LINE-1
Line-2 and Line-1
120VAC (108VAC-132VAC)
Line-1 and Ground
120VAC (108VAC-132VAC)
Neutral and Line-1
120VAC (108VAC-132VAC)

Troubleshooting
12
Voltage Check for 240V (4-Wire) Incoming Power
240VAC (Range of acceptability: 216VAC to 264VAC) should be read
between Line-2 and Line-1. 120VAC (Range of acceptability: 108VAC to
132VAC) should be read between Neutral and Line-1.
If ANY of the voltages read when checking the incoming power do not fall
within the indicated ranges of acceptability, then do not proceed with any
further troubleshooting until the incoming power issue is corrected.
Further Troubleshooting
If the system passes the incoming voltage check, the transformer and the
circuit boards’s glass fuse should be tested next. By testing the incoming
voltage, and the power to the board (the transformer, and glass fuse),
you can proceed with further troubleshooting without possibly missing an
underlying power related problem.
The Troubleshooting Test Points outlined on the next page will be
referenced throughout the rest of this section in explaining how to test the
various internal circuits of the control box. The page after next will explain
how to properly test the transformer and circuit board’s glass fuse. The
pages that follow that will explaining trouble shooting the other various
circuits of the control box.
NEUTRAL
LINE-2
LINE-1
Neutral and Line-1
120VAC (108VAC-132VAC)
NEUTRAL
LINE-2
LINE-1
Line-2 and Line-1
240VAC (216VAC-264VAC)

Troubleshooting
13
Troubleshooting Test Points
The following test points will be used when troubleshooting the control
box’s internal circuits:
1
2
3
4
5
6
7
8
9101112
13
14
15
16
18
19
20
17
10- Incoming Neutral
20- Incoming Line-2
30- Incoming Line-1
40- 20A Fuse (F1)
50- 20A Fuse (F2)
60- 20A Fuse (F3)
70- 2A Glass Fuse (F4)
80- Transformer Receptacle
90- Heater Line-2
10 - T18/Gas Terminal
11 - Heater Line-1
12 - IC Regulator Chip
13 - Pump-2 Hi-Speed Power
14 - 24Hr Circ & Audio Power
15 - Aux/Pump-2 Lo-Speed Power
16 - Pump-1 Lo-Speed/Timed Circ Power
17 - Pump-1 Hi-Speed Power
18 - Light (black wire)
19 - Light (white wire)
20 - Ozone Power

Troubleshooting
14
Transformer Voltage Checks
The transformers used in United Spas controls have 4 wires. There is a
black and a brown wire (These two wires are blue and a white on the 120V
transformers), and two yellow wires. It should be possible to slide the pins
of your voltmeter/multi-meter into the top of the transformer plug (Which
is plugged into Testing Point 8) where the wires enter the plug. 240VAC
(Range of acceptability: 216VAC to 264VAC) should be read between
the black and brown wires on a 240V transformer or 120VAC (Range of
acceptability: 108VAC to 132VAC) between the blue and white wires on a
120V Transformer. If you are not getting a reading of the incoming power
within the acceptable range, and you’ve confirmed the incoming voltage
with the previous voltage checks, then the 2A Glass Fuse (Testing Point 7)
should be checked next.
If the incoming voltage checks out, proceed to test the output voltage.
12VAC (Range of acceptability: 12VAC to 14VAC) should be read between
yellow wires. If the voltage read between the yellow wires does not fall
within the indicated ranges of acceptability, then do not proceed with any
further troubleshooting until the transformer has been replaced. If the
incoming voltage read does not fall within the range of acceptability, re-
check the incoming voltage to the control box.
Checking the 2A Glass Fuse
Put one probe of your voltmeter/multi-meter on Line-2 (Testing Point 2),
and the other on the RIGHT fuse clip of the 2A Glass Fuse (Testing Point
7). You should get a voltage reading equal to the control box’s incoming
power voltage (240VAC or 120VAC). Leaving one probe on Line-2, move
the other probe to the LEFT fuse clip. You should again get a voltage
reading equal to the incoming power voltage, if you do not, then the fuse
has blown and needs replacing.

Troubleshooting
15
Troubleshooting the Circuit Board’s Low Voltage Circuit
If the control is non-operational, or the topside display is completely blank,
but the incoming voltage, transformer, and glass fuse all test okay, the
circuit board’s IC Regulator Chip should be tested.
Checking the IC Regulator Chip
Be sure your voltmeter/multi-meter is set to DC Volts to test this component.
Place one probe of your voltmeter/multi-meter on the IC Regulator Chip’s
(Testing Point 12) mounting nut, and the other on the RIGHT most pin
coming out of the top of the chip. You should get a voltage reading of
approximately 15VDC. If not, the board’s bridge rectifier (marked BR1 on
the board) has failed and needs to be replaced.
Next, leaving one probe on the mounting nut, move the other probe to the
LEFT most pin coming out of the top of the chip. You should get a voltage
reading of approximately 5VDC. If not, the IC Regulator Chip itself has
failed and needs to be replaced.
Troubleshooting the Light Circuit
With the light turned on at the topside, place one probe of your voltmeter/
multi-meter on Testing Point 18 (Light-B) and the other on Testing Point
19 (Light-W). You should get a reading of 12VAC if the light jumpers are
set to Low Voltage, otherwise you should read high voltage. If you read
no voltage, and the incoming power and transformer tested okay, then the
light relay has failed. If you read voltage, but the light does not function,
then the light bulb itself has failed and needs replacing.

Troubleshooting
16
Troubleshooting the Pumps/Blower/Ozone
If one or more of the pumps/blower/ozone are non-operational, re-check
that the code settings have been programmed correctly for the equipment
configuration. If programmed correctly, the main fuses and output voltages
should be checked.
Checking the Main Fuses
On the B7 board, the Circulation Pump, Pump-1, Audio, and ozone all
use the F1 Fuse (Testing Point 4). The Blower, Pump-3, or Pump-2 (Low-
Speed) uses the F2 Fuse (Testing Point 5)., while Pump-2 (Hi-Speed)
uses the F3 Fuse (Testing Point 6). Check the fuse of the non-operational
component by putting one probe of your voltmeter/multi-meter on Line-
2 (Testing Point 2) and the other on the RIGHT fuse clip of the fuse in
question. You should get a voltage reading equal to the control box’s
incoming power voltage (240VAC or 120VAC). Leaving one probe on Line-
2, move the other probe to the LEFT fuse clip. You should again get a
voltage reading equal to the incoming power voltage, if you do not, then
the fuse has blown and needs replacing.
Checking the Output Voltages
The output power pin of each component are located at the top left of the
circuit board (Testing Points 13-17, and 20). To test, activate the desired
component that is being tested. Pump-1, Pump-2, and Aux can be activated
by simply pressing their corresponding button on the topside. The ozonator
is only activated during filtration cycles, so you’ll have to force the system
to filter to test the ozone power. Activation is not necessary for 24hr Circ
pump or Audio as these components are constantly powered. Next place
one probe of your voltmeter/multi-meter on Line-2 (Testing Point 2), and
the other on the testing point for the component in question. If the fuse
checks out, but no voltage is read on the power terminal of the component
in question (while the control is of course calling for that component to
run), then the relay for that component has failed.

Troubleshooting
17
Troubleshooting the Heating Circuit
If the heater is non-operational or the unit is not heating properly, re-check
that the code settings have been programmed correctly for the hot tub’s
heating configuration. If programmed correctly, the heating circuit should
be tested.
Testing the Heating Element
To test the heating element, you must first make sure the topside is calling
for heat (The display should be flashing the heat message - HEt). Then
place one probe of your voltmeter/multi-meter on Testing Point 11 (Heater
Line-1), and the other on Testing Point 9 (Heater Line-2). You should get a
voltage reading equal to the control box’s incoming power voltage (240VAC
or 120VAC). If that is the case, but the water is not getting heated, then the
heating element has failed/burnt-out/dry-fired.
If the voltage reading was not equal to the incoming power voltage, then
proceed with checking the heater relays.
Testing the Heating Relays
Place one probe of your voltmeter/multi-meter on Line-1 (Test Point 1), and
the other on Test Point 9 (Heater Line-2). You should get a voltage reading
equal to the control box’s incoming power voltage (240VAC or 120VAC). If
that is the case, proceed to the next test. If you read no voltage, however,
then the K10 relay has failed.
If the K10 relay checks out, place one probe of your voltmeter/multi-meter
on Line 2 (Test Point 2) and the other on Test Point 10 (T18/Gas Terminal).
You should get a voltage reading equal to the control box’s incoming power
voltage (240VAC or 120VAC). If that is the case, proceed to the next test. If
you read no voltage, however, then the K1 relay has failed.
If the K1 relay checks out, place one probe of your voltmeter/multi-meter
on Line 2 (Test Point 2) and the other on Test Point 11 (Heater Line-1). You
should get a voltage reading equal to the control box’s incoming power
voltage (240VAC or 120VAC). If you read no voltage, then the K9 relay
has failed.

Replacing Relays
18
Replacing Relays
Should a relay fail, it can be replaced by anyone qualified to solder or work
on electronics. Replacement relays should be available from anywhere
United Spas products are sold.
Relay Locations
K3
K10- Temp Relay
K20- Pump-1 Lo-Speed Relay
K30- Pump-1 Hi-Speed Relay
K40- Pump-2 Low & Aux Relay
K50- Ozone Relay
K2
K6 K5
K7 K4
K9 K1 K10
K60- Light Relay
K70- Pump-2 Hi-Speed Relay
K90- Hi-Limit-L1 Relay
K10 - Hi-Limit-L2 Relay

Light
Cir Pump
Pump 1
Aux
Pump 2
Audio
He
a
High Limit Sensor
Top Side
Temp Sensor
Ozone
Gas
Heater
To Neutral for 120V
To Line-2 for 240V
If the Component is 120V: Conne
If the Component is 240V: Conne
Heater Lin
e
Hi
L
K2K3
K4K7
P-1 Hi P-1 Lo
AUX or P-2 LoP-2 Hi
P-2 Hi
Aux - P-2 LoP-1 Lo
P-1 Hi
Light
Ozone
B
W
Circ - Audio
Bri
d
Voltage Regulator
K6
Light