KELCO T20 TIMER
INSTALLATION & PROGRAMMING INSTRUCTIONS
KELCO Engineering Pty Ltd
Sydney Australia
www.kelco.com.au
Table Of Contents
Page
Warning Symbols Explained.......................................................... 1
Important Safety Instructions......................................................... 2
Overview........................................................................................ 3
Installing the T20........................................................................... 4
Electrical........................................................................................ 5
Blackout or Brownout.................................................................... 6
Cable Gland Assembly................................................................... 7
The Heavy Duty (HD) Terminal...................................................... 8
Electrical Limitations...................................................................... 9
Circuit Diagrams............................................................................ 10
The 12VDC T20 Timer................................................................... 14
T20 Controls and Terminals........................................................... 15
Remote Flow Switch Input............................................................. 17
Suitable Flow Switches.................................................................. 19
Purging the T20............................................................................. 20
Programming the T20 Timer.......................................................... 21
Basic Operation............................................................................. 22
T20 Table of Limitations................................................................. 23
Advanced Functions...................................................................... 24
Batch Control................................................................................. 25
Delayed Restarting........................................................................ 26
Cyclic Running............................................................................... 27
Anti-Cycling.................................................................................... 28
Burst Pipe Detector........................................................................ 29
LCD Screen Backlight, Program Lock.......................................... 30
Program Lock................................................................................ 30
Maintenance.................................................................................. 30
Warranty......................................................................................... 31
WARNING
This symbol is intended to alert the user
to the presence of important operating
and maintenance instructions in the literature accompanying the T20 timer
WARNING
This symbol is intended to alert the user
to the presence of un-insulated “dangerous voltage” within the timer’s enclo-
sure that may be of sufcient magnitude
to constitute a risk of severe electric
shock.
1
IMPORTANT SAFETY
INSTRUCTIONS
• Read these instructions.
• Keep these instructions.
• Heed all warnings.
• Follow all instructions.
• Do not allow water to enter this timer.
• Install this timer per the manufacturer’s instructions.
• Do not install this timer near any heat source such as
radiators, gas heaters, stoves or any other appliance that produces heat.
• Do not modify this timer in any way.
• Do not drill holes in this timer’s casing.
• Refer all installation and servicing to qualied service personnel.
• Servicing is required when the timer has been damaged in any way,
such as submerged in water, exposed to re, dropped or objects dropped
on it. Exposed to moisture or water when the timer’s lid is removed.
WARNING
Please read these installation and operating instructions carefully and fully before installing or
servicing this timer. The T20 is a mains voltage
device. Death or serious injury may result if this
product is not correctly installed and operated.
2
Overview
When connected to an external ow switch the T20 timer provides a pumping
system with a set of useful time and ow based functions. The T20 can be congured in a variety of ways to control the pump and to protect it. It can be set to
start a pump in spite of an initial lack of ow and to then do no more than protect
it against loss of ow. The T20 can also be programmed to simulate a complex
pump control panel. This document sets out in detail the installation and functions
of the T20 timer and some of the main ways in which it can be used in pumping
and irrigation systems.
WARNING
Without its lid in place the T20 timer is not water
resistant and presents a potential shock hazard.
Take great care not to splash water onto the T20
when the lid is not in place. Always replace the
lid and fully tighten its 6 securing screws immediately after any changes to the timer’s settings
are made.
INSTALLING THE T20 TIMER
Location
Where possible install this timer in a location that is sheltered from direct exposure to the weather. The T20 is weatherproof and is supplied with a protective clip
on cover. However, to ensure a long reliable life we recommend it be protected
from direct exposure to the sun and rain. Intense sun light will eventually cause
discolouration and degradation of the timer’s housing. It is therefore advisable to
protect the timer from the weather if possible.
The T20 timer should be installed on a wall or on a bracket attached to a pump
or its pipework. Where large pump motors are to be directly controlled, mount the
T20 as close as practical to the supply and pump to keep heavy cable runs to a
minimum.
3
Installing the T20
The T20 timer is supplied as two separate assemblies, the wall mounting bracket
and the electrical housing. The mounting bracket should be installed rst by
securing it to a wall or to a plate attached to the pipework or pump. The drilling
pattern is shown below.
60mm
4 X 6mm
Holes
74mm
Attach the electrical housing to the wall bracket by engaging the two toes on the
bracket into the two notches in the retainer plate on the underside of the electrical housing. Secure the electrical housing to the wall bracket using the large hex
headed red bolt supplied in the kit. Tighten the red bolt using a broad bladed
screwdriver or small socket wrench. Do not overtighten it.
4
Electrical
WARNING
All electrical work associated with the T20 must
be carried out by qualied electrical personnel
and all electrical work must conform to AS/NZ
standards and to local wiring rules. For mains
voltage applications we recommend the supply to the T20 be isolated by an RCD that has a
maximum trip current of 30mA.
Introduction
The T20 timer is designed to directly control single-phase pump motors to 3.75kW.
No interposing contactor is required for such applications. If a supply neutral or
transformer is available, the timer can also be used to control 3 phase pump motors via an appropriate interposing contactor that has a suitable coil voltage.
The T20 timer requires a 220V to 240V AC 50Hz supply when operated from the
mains. It can also be operated from an 18 to 24V AC or DC supply by utilising the
low voltage active terminal LV and common neutral terminal N, see the included
wiring diagrams. When operated from a low voltage DC supply the terminals LV
and neutral N are not polarity sensitive. The T20 timer requires a stable supply
voltage in order to operate correctly. Pay particular attention to cable sizes, and
ensure cables are adequate for the specic pump motor load. This is particularly
important where long cable runs are to be used in the installation. If the voltage
drop associated with the starting of the pump motor is excessive the T20 will automatically reset and this may cause the pump to jog. Jogging can snap the main
spindle of a pump very easily, so please take all precautions to ensure the voltage
supply to the T20 is stable and that the current carrying capacity of the cable used
is adequate for the job.
5
Brownout Or Blackout
If a blackout or brownout occurs the T20 timer will not retain memory of where in
its run or stop cycles it may have been. When power resumes, the T20 will reboot
and resume running. A manual reboot can be done at any time by pressing the
timer’s reset button.
WARNING
The T20 timer derives low voltage for its operation from a non-isolated reactance power supply (not through an isolated transformer). All
external devices connected to the T20 must be
earthed and must be regarded as operating at
full mains potential. For all mains voltage applications we recommend the supply to the T20
be isolated by an RCD that has a maximum trip
current of 30mA.
Cables
The T20 timer has 3 X M20 cable glands. As supplied the cable glands are
blanked off. To use the glands rst punch out the blanking barriers using a suitable punch. The cable glands can accept cable from 7 to 9mm diameter. See
attached sketch for assembling the cable gland components. The timer is supplied with a set of steel crimp rings. The crimp rings are to provide strain relief for
the timers cables. To use the crimps, place one on the cable approximately 4mm
below the end to the cable’s outer sheathing. Crimp the two ears of the ring at
using bull nosed pliers. Pull the cable back through the cable gland until the crimp
ring’s ears are fully engaged in the two slots in the gland housing.
6
Cable Gland Assembly
Relays
The T20 timer houses 2 relays. The contacts of both relays are voltage free and
are normally open. The relays are marked Relay 1 and Relay 2 on the terminal
block. Relay 1 is the primary relay and is used to control the pump motor. It has
an electrical rating of 30 Amps (resistive) at 240VAC. Relay 2 is a 16 Amp (resistive) 240VAC rated relay and is used for actuating an external alarm. The relays
built into the T20 timer are not suitable for the direct control of DC motors.
7
The HD (Heavy Duty) Terminal
WARNING
The HD terminal must be left unused or only
ever be linked to the relay terminal Relay 1 Normally Open. It must never be used for any other
purpose and it must never be connected to any
external device. Under no circumstances connect the HD terminal to the terminals of Relay 2.
The HD terminal must be regarded as live at all
times and at full mains potential
The T20 timer contains a solid-state switch (HD Heavy Duty drive) that can be
used to protect the contacts of Relay 1 by eliminating the destructive arcing
caused by the starting and stopping of pump motors. The solid-state switch is
accessible from the HD (Heavy Duty) terminal on the terminal block. We recommend the HD drive be used whenever the timer is used to directly control a pump
motor. The HD drive should not be used when the T20 is connected to external
timers, contactors, relays or to any other external device where voltage free contacts are required. It is strictly intended for the direct control of highly inductive
AC motor loads. The HD terminal and the timer’s built in relays must never be
connected to a DC motor under any circumstances.
When the HD terminal is linked to the terminal Relay 1 Normally Open, the HD
drive in effect parallels a 40Amp solid state switch across the relay’s normally
open contacts. This increases the momentary current carrying capacity of the
relay’s contacts to well over 70 Amps. The solid state HD drive is only activated
for a short period when the pump starts and stops. It effectively handles the high
inrush current associated with the pump starting, and it provides a current path for
the destructive back EMF associated with the pump motor stopping.
To use the HD drive place a heavy link wire, 1.0mm or 1.5mm Sq between the HD
terminal and the Normally Open terminal of Relay 1.
8
VOLTAGE LIMITS ON TERMINALS A & N
Maximum Supply Voltage 250VAC 50Hz
Minimum Supply Voltage 160VAC 50Hz
VOLTAGE LIMITS ON TERMINALS LV & N
Maximum Supply Voltage 25VAC 50Hz or 25VDC
Minimum Supply Voltage 18VAC 50Hz or 18VDC
RELAY 1 CONTACT RATING
16A at 250VAC Resistive Load
16A at 30VDC Resistive Load
RELAY 2 CONTACT RATING
16A at 250VAC Resistive Load
16A at 30VDC Resistive Load
WARNING
Do not connect any supply greater than 25VAC
or DC to the LV terminal on the T20 timer. The
LV terminal is only for use with a low voltage
supply of less than 25V AC or DC. If a voltage
greater than 25V AC or DC is connected to the
LV terminal of the T20 timer the timer will be
damaged and any warranty on the product will
be void.
9
Circuit Diagrams
The following pages give some examples of ways the T20 timer
can be wired.
Please note all electrical work associated with the T20 timer must be car-
ried out by suitably qualied electricians
and must conform to AU/NZ wiring rules.
FOR PUMP MOTORS TO 2.4 kW
CONNECTIONS FOR PLUG & PLAY INSTALLATION
10
LOW VOLTAGE AC CONNECTIONS
RELAY CONTACTS ARE VOLTAGE
FREE AND CAN BE USED TO SWITCH
A CONTACTOR OR TO DIRECTLY
CONTROL A PUMP MOTOR. SEE TEXT
FOR INFORMATION ON THE LIMITATIONS OF THE RELAY CONTACTS AND
HOW TO USE THE HD TERMINAL.
LOW VOLTAGE DC CONNECTIONS
RELAY CONTACTS ARE VOLTAGE
FREE AND CAN BE USED TO SWITCH
A CONTACTOR OR TO DIRECTLY
CONTROL A PUMP MOTOR. SEE TEXT
FOR INFORMATION ON THE LIMITATIONS OF THE RELAY CONTACTS AND
HOW TO USE THE HD TERMINAL.
REMOTE FLOW SWITCH. CONTACTS ARE
NORMALLY OPEN.
18 TO 25 VDC 150mA MINIMUM
SUPPLY POLARITY IS NOT IMPORTANT BUT
IF THE EXTERNAL INPUT IS USED IT MUST BE
SOURCED FROM THE SUPPLY POSITIVE AS
SHOWN HERE.
18 to 25VAC SUPPLY
NEUTRAL
ACTIVE
REMOTE FLOW SWITCH. CONTACTS ARE NORMALLY OPEN.
11
CONTROL OF A SINGLE PHASE PUMP MOTOR WITH REMOTE FLOW
SWITCH INPUT AND AN EXTERNAL ALARM
THIS LINK MUST BE USED WHENEVER THE TIMER IS DIRECTLY
CONTROLLING A SINGLE PHASE
PUMP MOTOR, AS SHOWN HERE.
ACTIVE
MAINS VOLTAGE SUPPLY
220VAC to 240VAC
NEUTRAL
PUMP
MOTOR
ALARM LIGHT OR SIREN 220 ~
SINGLE PHASE 220 ~ 240VAC
MOTOR MAXIMUM MOTOR LOAD
3.75kW
REMOTE FLOW SWITCH. CONTACTS ARE NORMALLY OPEN.
240VAC DEVICE 16A MAXIMUM
LOAD RESISTIVE
CONTROLLING A 3 PHASE PUMP WITH REMOTE FLOW SWITCH
INPUT AND AN EXTERNAL ALARM
REMOTE LEVEL OR PRESSURE
SWITCH. CONTACTS ARE
NORMALLY OPEN.
ALARM OR SIREN 220-240VAC DEVICE
16A MAXIMUM LOAD RESISTIVE.
COIL
3 PHASE PUMP
CONTACTOR
12
N
A1
3 PHASE SUPPLY
A2
A3
CONTROLLING A 240VAC SINGLE PHASE PUMP MOTOR WITH THE T20
MOTOR
TIMER POWERED FROM A LOW VOLTAGE AC SUPPLY
THIS LINK MUST BE USED
WHENEVER THE CONTROLLER IS
DIRECTLY CONTROLLING A SINGLE
PHASE PUMP MOTOR, AS SHOWN
HERE.
NEUTRAL
18 to 25VAC SUPPLY
ACTIVE
MAINS VOLTAGE SUPPLY
220VAC to 240VAC
ACTIVE
NEUTRAL
PUMP
MOTOR
SINGLE PHASE 220 ~ 240VAC
MOTOR MAXIMUM MOTOR LOAD
3.75kW
REMOTE FLOW SWITCH. CONTACTS ARE NORMALLY OPEN.
BASIC 3 PHASE PUMP CONNECTIONS
3 PHASE PUMP
COIL
CONTACTOR
13
SUPPLY NEUTRAL
N
A1
3 PHASE SUPPLY
A2
A3
12VDC T20 TIMER
A special 12VDC version of the T20 timer is available for battery operation and
for use in solar pumping systems. Functionally the 12VDC model is exactly the
same as the mains voltage model except for the terminal block markings. On the
12VDC model the active and neutral terminals are replaced by a positive + and
a negative – terminal. Supply voltage across the positive and negative terminals
must never exceed 14VDC or the timer will be damaged. The supply terminals
are reverse polarity protected. However, the timer will simply not operate unless
the supply polarity is correct.
When connecting a remote ow switch to the 12VDC T20 timer the supply to the
ow switch must be taken from the positive terminal on the T20 timer. The ow
switch and its connecting circuit will operate at 12VDC.
CONTROLLING A 220 ~ 240 VAC SINGLE PHASE PUMP MOTOR WITH THE T20 TIMER POWERED
THIS LINK MUST BE USED
WHENEVER THE CONTROLLER IS
DIRECTLY CONTROLLING A SINGLE
PHASE PUMP MOTOR, AS SHOWN
HERE.
ACTIVE
MAINS VOLTAGE SUPPLY
220VAC to 240VAC
FROM A 12V DC SUPPLY
WIRING DIAGRAM
12VDC CONTROLLER ONLY
SUPPLY 11 ~ 14 VDC
NEUTRAL
REMOTE FLOW SWITCH. CON-
TACTS ARE NORMALLY OPEN.
SINGLE PHASE 220 ~ 240VAC
MOTOR MAXIMUM MOTOR LOAD
3.75kW
IMPORTANT
THE SUPPLY TO THE REMOTE FLOW
SWITCH MUST BE SOURCED FROM
THE SUPPLY POSITIVE AS SHOWN
HERE.
14
T20 Controls and Terminals
15
No. Description Function
Mains Voltage Active
1
Terminal
Supply Neutral
2
Terminal
Low Voltage Active
3
Terminal
Alarm Relay Terminal
4
Normally Open
Alarm Relay Contact
5
Common
Remote Input Terminal This is the remote switch input terminal for connection
6
Pump Relay Terminal
7
Normally Open
Pump Relay Terminal
8
Common
Heavy Duty Drive Ter-
9
minal
10 Program Button Press this button to program the T20 timer.
Timer Light (Red or
11
Green)
12 Up Button
Pump Start Light (Red or
13
Green)
14 LCD Screen
15 Down Button
16 Reset Button
Flow Status Light
(Red or Green)
17
For all mains voltage applications this is the supply
connection.
For all applications this is the supply neutral connection.
This is the supply active terminal for all low voltage
applications.
This terminal is for connecting an external alarm. It is
voltage free.
This terminal is for connecting an external alarm. It is
voltage free.
to an external ow switch.
This terminal is for connection to a pump motor or
contactor.
This terminal is for connection to a pump motor or
contactor.
Link this terminal to the relay 1 Normally Open terminal
when directly controlling pump motors.
This light is green whenever a run timer is running. It
turns red whenever a stop timer is running.
Use this button when programming the ow switch to
enter data.
This light is red whenever the pump is stopped and it is
green whenever the pump is running.
The LCD screen displays information whenever the
timer is switched on.
Use this button when programming the T20 to enter
data. It also turns on the LCD backlight.
This button reboots the T20 timer each time it is
pressed.
This light is green whenever ow is detected and red
when no ow is detected. It indicates the T20’s microprocessor has read the true state of the external ow
switch.
16
Remote Flow Switch Input
An external ow switch with voltage free contacts or a set of external relay contacts can be used to start and stop a pump under the control of the T20. The
supply to the external switch must be taken from the (LV) terminal (Low Voltage
active terminal) of the T20 timer when the timer is powered from the mains or from
a 24VAC source. The T20 must always be powered from the same source as the
supply to the external ow switch. The supply to the remote ow switch on the
T20-12 (low voltage DC model) must be taken from the supply positive terminal.
In all cases the external ow switch return wire must be connected to the Remote
input (R) terminal on the T20. The Supply to the external ow switch will range
from 12 to 24 VDC or from 20V to 35V AC depending on the model of the timer
and on the supply voltage.
WARNING : The low voltage source available at the LV terminal is non-isolated and in terms of insulation must be regarded as operating at full mains
potential whenever the T20 timer is powered from the mains.
The remote ow switch can be installed some distance from the T20 timer. The
maximum distance is limited by cable resistance and capacitance. The total ca-
ble resistance must not exceed 5K Ohms with the remote ow switch’s contacts
closed. The total capacitance of the cable must not exceed 25nF with the re-
mote ow switch’s contacts open. Wires to the remote ow switch should be run
separately from power carrying cables. Do not run the remote ow switch wires
in a conduit that also contains power cables. Capacitive coupling between the
adjacent cables may cause false triggering of the T20’s remote input. For cable
runs longer than 150 metres suggest using 2 separate wires to reduce capacitive coupling between the adjacent wires. When set up this way cable resistance
becomes the limiting factor for distance. The table that follows sets out the resistance of typical copper wire of various diameters.
17
Nominal Cross Section of copper
wire in square millimetres
0.2 95.30
0.5 36.20
0.75 24.13
1.0 18.10
1.5 12.10
Note: Resistance may vary depending on the wire standard and the actual construction of the wire. The cable resistance refers to the total resistance out to the
remote ow switch and back again, as measured at the T20 timer across the 2
remote ow switch connection wires with the ow switch contacts closed.
Example
A ow switch is located 1000 metres from the T20 timer. Two separate wires each
0.2mm^2 are run to the remote ow switch (total wire length is 2000 metres). The
resistance as measured across the 2 wires back at the T20 (with the ow switch‘s
contacts closed is 190 Ohms. This is well under the 5,000 Ohm limit. The remote
input to the T20 will operate properly provide the wires are separated by sufcient distance that the capacitance between them is less than 25nF. Capacitance
should be measured between the wires when the remote ow switch’s contacts
are open, and it must be less than 25nF.
Resistance in Ohms per 1000 Me-
tres
Remote Flow Switch
The remote ow switch should be suitable for low voltage low current operation.
In particular its contacts should only require a low wetting current. The current in
the remote loop only runs to a few milliamperes and requires a ow switch that
will conduct when closed under low current conditions. Reed switches are the
preferred method of controlling the remote input to the T20 timer. Suitable Kelco
ow switch models are listed in the following table.
18
Suitable Flow Switches
The ow switches listed below all use reed switches as their output device and
are suitable for use with the T20 timer.
Paddle ow switches
with BSP or NPT threads
and poly or stainless
bodies.
F20-S-R P20-B, P20-C TW20-S-R
F20-SS-R P25-B, P25-C TW20-SS-R
F21-S-R UB20-B, UB20-C TW21-S-R
F21-SS-R UB25-B, UB25-C TW21-SS-R
F25-B C20-B
F25-C C25-B
Full technical details of the ow switches listed above can be downloaded from
Inline ow switches with
poly, brass or stainless
bodies and BSP or NPT
threads.
www.kelco.com.au
Trailing wire ow Switches with poly or stainless
bodies and BSP or NPT
threads.
19
Purging the T20 Timer
The T20 timer is supplied unlocked and pre-loaded with a simple program. It is
set up with a 5 second start override time and a 5 second run-on time. All other
functions are turned off. With the default program loaded, the T20 will start a
pump in spite of an initial lack of ow, run the pump for 5 seconds and expect
to establish ow past the paddle of its remote ow switch within this start up
time. Given ow is established it will then run the pump continuously while ow
is present and it will shut the pump down if ow is interrupted for more than 5
seconds or if ow stops completely.
You can restore the T20 to this default state at any time by pressing and holding
down the (P) button and pressing the (R) reset button at the same time. Release
the (R) button and then release the (P) button. The timer light will then ash rapidly red to indicate the process is complete. Doing this removes any settings you
may have entered and restores the T20 to its original default state. You can then
enter new settings or just press reset (R) again and run the pump.
Introduction to Programming
The T20 ow switch timer includes a set of functions that can be set up to control
a pump. The functions range from a simple override on start timer that allows a
pump to start in spite of an initial lack of ow, through to a range of sophisticated
timing and ow based sequences. The functions are independently accessible
and adjustable through the T20’s simple programming interface. The pages that
follow set out what each function does and how to set it up.
The actual selection of a suitable set of functions must be decided prior to programming and will depend on what level of control the pumping system requires.
In order to achieve the best performance from this ow switch observe the following basic rules.
1) Use the least number of functions possible. Do not program in functions you
do not specically require, as to do so will make the system’s operation unnecessarily complicated and may introduce unpredictable interactions that could cause
the T20 to behave in a manner you had not anticipated.
20
2) The best way to switch off a function that you have previously selected and
subsequently decided not to use is to purge the entire program and restore it to
its default state rather than simply switch the particular function off. Purging the
program ensures the functions are properly disabled and their stored values are
all set to zero or off. To purge the program press the (P) button and the (R) reset
button. Release the reset button while still holding the (P) button down, then release the (P) button. The LCD screen will display the message “Settings Cleared,
Press (P) to Continue” Press (P) and then step through the program making your
new selections as you go.
3) Set realistic and sensible values into the various functions. For example, do
not set a pump to cycle on and off rapidly. Always set the T20’s running and stopping times to realistic values.
Programming The T20 Timer
The T20 timer is fully programmable; it accepts input via 4 push buttons. The buttons are marked (P) for programming, Up and Down for data entry and a reset
button (R). Pressing the (P) button during normal operation stops the pump and
allows entry to the timer’s menu. Subsequent pressing of the (P) button steps
you through the menu from one option to the next. Each option can be adjusted
using the up and down buttons. Pressing the (P) button stores the settings you
make into the timer’s memory and steps you to the next option. When you reach
the end of the option list the timer asks you to accept the settings you have made
and to press the (P) button to resume normal running. You can automatically
save any changes you have made and exit out of the menu at any stage during
programming by simply pressing the (R) reset button. The settings you make are
non-volatile and are recorded in the timer’s memory. Your setting will not be lost
if the timer is switched off for extended periods. When the unit is switched back
on the timer will boot up and operate using the setting you previously recorded in
its memory.
21
Basic Operation
Purging the T20 timer (pressing the (P) button and then pressing the (R) reset
button) automatically loads in a 5 second start-up time and a 5 second run-on
time. This is the factory default setting for the T20. All other functions will be
turned off or set to zero. If you subsequently press the (P) button while the pump
is running, the pump will stop and the LCD screen will display the Kelco splash
screen and the timer’s model number. Pressing the (P) button again steps you to
the rst selection in the menu, the start-up timer.
Start-up and Run-on Timers
The start-up timer is set to 5 seconds as the factory default. You can increase
or decrease this by pressing the up or down buttons and then pressing the (P)
button to step to the next function, the run-on timer. The run-on timer is also set
to 5 seconds by default and again you can increase or decrease this by pressing
the up or down buttons. The start-up timer has a range of 0 to 240 seconds and
the run-on timer can be set from 0 to 900 seconds. Both the start-up and run-on
timers are self terminating. This means they cancel out their runs and revert to
normal pump running as soon as ow is detected rather than running for the full
time that you have entered. In addition, the run-on timer automatically resets its
clock each time ow is detected. This feature means the ow switch connected
to the T20 will ignore entrained gas in the pipe system. The ow has to remain
continuously off for whatever time you set on the run-on timer for the pump to
stop. The pump may be running dry for the period you set on the run-on timer so
take care not to set a run-on time that is longer than absolutely necessary.
Once you have set the run-on timer and pressed (P) to conrm its setting you are
presented with a screen that asks if you want to use the advanced functions of
the T20 timer. If your application only requires dry run protection for a pump and
a start override to get the pump going in spite of an initial lack of ow then you
will not require the advanced functions. In this situation just accept the default
“NO” and press (P). You will then be asked to conrm your choice and press the
(R) reset button to run the pump. If you select “NO” to the conrmation question
the T20 will step back to the top of the menu and allow you to change whatever
settings you want.
22
T20 Table of Limitations
Ambient Temperature Range 1ºC to 50ºC
Ingress Protection Rating IP67
Start-up Timer
Run-on Timer
Pre-Start Delay Timer
Batch Controller
Delayed Restarting
Cyclic Running & Stopping
Anti-Cycling
Burst Pipe Detector
Adjustable from 1 second to 4 minutes
in 1 second increments.
Adjustable from 1 second to 15 minutes
in 1 second increments.
Adjustable from 1 second to 4 minutes
in 1 second increments.
Adjustable from 1 minute to 99 hours
59 minutes in 1 minute increments.
Adjustable from 1 minute to 99 hours
59 minutes in 1 minute increments.
Running and stopping times both adjustable from 1 minute to 99 hours 59
minutes in 1 minute increments.
Adjustable from 1 motor start per hour
to 1800 motor starts per hour.
Adjustable from 1 minute to 99 hours
59 minutes in 1 minute increments.
23
Advanced Functions
The T20 timer includes a set of advanced functions that extend the capability of
the timer well beyond basic loss of ow protection. The advanced functions are
directly accessible by moving beyond the more basic start-up and run-on timers
previously described. There follows here a detailed description of each of the
advanced functions. Advanced functions can be used singularly or in combination with other advanced functions as well as with the start-up and run-on timers.
Some advanced functions conict with others and the T20 timer will automatically
step over conicting functions based on your progressive selections.
Pre-Start Delay Timer
On moving into the advanced functions section of the T20’s menu you are rst
presented with the option to include a pre-start delay time. The pre-start delay
timer delays the starting of the pump for a selectable period. It can be set from
zero to 240 seconds (4 minutes) in 1 second increments. If you choose to use
this timer the actual starting of your pump will be delayed by whatever delay you
set this timer to. Each time the T20 is switched on it boots up but prevents the
actual starting of the pump for the set period. As soon as the set time has elapsed
the pump will start and run normally. The pre-start timer can be used to allow
peripheral equipment time to boot up. For example, some VS drives require a
few seconds to stabilise and the T20’s pre-start timer can hold off the starting of
the pump until the system has stabilised. The pre-start timer can also be used to
stage or stagger the starting of multiple pumps. If you want to use the delayed
starting function press the up or down buttons to display “YES” and then press the
(P) button. You will then be able to enter your required delay period using the up
and down buttons. The range of adjustment is zero to 240 seconds in 1 second
increments. When you have entered your required time press (P) to move on to
the next function.
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Batch Control
The batch control function built into the T20 timer lets you program into the timer
a set running time for the pump. The range of adjustment is 1 minute to 99 hours
59 minutes in increments of 1 minute. The running of the set time can be initiated
by powering up the T20 or by pressing the (R) reset button.
If ow is lost during a batch run, due to the pump running dry or a valve closing,
the T20 will shut down the pump. If ow subsequently resumes the batch control-
ler will re-initiate its run from the beginning. It will not resume running from the
point in its previous run that it shut down at. This function can be used in tank lling applications to send a set volume of water to a tank but to terminate the batch
run when the ow stops due to the oat valve in the tank closing.
Batching With Additional Functions
If you choose to use the T20 batch controller, you can also use additional functions at the same time. Once you make the choice to use the batch controller
the T20 automatically makes available to you functions that will work while the
batch controller is in operation. Functions that will not work with the batch controller are automatically stepped over by the menu program. Functions that will
not work include cyclic running and burst pipe detection.
If you choose to use a function such as delayed restarting please be aware that
when the delayed restart is invoked the batch controller resets its run time to
your original entered value. At the end of the delay time the pump will start and
run your set batch from the beginning. This process will repeat each time the
pump shuts down for any reason, the batch counter will reset and run your batch
from the start.
If you choose to use the batch controller the T20’s cyclic running function will be
disabled. If you choose not to use batch running then cyclic running will appear
in the menu. Cyclic running can be used for batch processes. To do this set the
cyclic running time to some value and set the cyclic stopping time to zero. In
effect, zero stopping time means innite stopping time as there is no dened set
stop time. Set up this way the T20 will run for whatever time you have entered
into the cyclic running run time and will then stop. This batching process can be
repeated by pressing the reset button.
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Delayed Restarting
If you set this option to on, each time the pump stops, due to ow stopping the
T20 will prevent the pump from restarting for the set period of time. The delay
time can be set from zero to 99 hours 59 minutes in increments of 1 minute. Delayed restarting is a form of anti-cycling and cyclic running, wherein the pump is
limited in its ability to cycle on and off by preventing it from restarting for a set time
period. Its uses include preventing rapid cycling if the system’s air cell becomes
water logged or if a fault develops in the system.
If you choose to use the delayed restarting function and press (P) you will be
asked to enter the delay hours and minutes. You will then be asked if you
want automatic starting at the end of the delay period. If you choose yes to
this question the T20 will automatically start your pump at the end of the delay period. If you choose no the T20 will only start the pump after the de-
lay if ow pushes the paddle of the remote ow switch into the on position.
You may choose to set the delayed restart to perhaps 12 hours. At the end of
the 12 hour period the pump will automatically start and if the tank level is low,
the pump will run continuously until the tank lls and the oat valve in the tank
closes. If however, there has been no draw-off from the tank during the 12 hour
period, the automatic restart at the end of the delay will start the pump and run it
for whatever period you have set on the start timer (perhaps a few seconds). The
ow switch connected to the T20 will sense no ow because the oat valve will
still be closed. The T20 will then shut down the pump and again wait for 12 hours
before attempting to start the pump. Using this technique prevents the pump from
hunting on and off when the tank is full because of slight leakage from the oat
valve or pipework. It allows you to set the pump to only operate after a chosen
delay, and if there has been no usage of water, to test the system for demand by
momentarily starting, and only run the pump if there is a genuine call for water.
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Cyclic Running
The T20 timer can be programmed to run and stop a pump for set periods of time.
Both the running and stopping times can be set to any value you choose from 1
minute to 99 hours 59 minutes in increments of 1 minute. The cyclic running op-
tion is highly exible. The run and stop timers are independent of each other. If
a set running and stopping time are programmed in, the T20 will run the pump for
whatever time it is set to and then stop for the time set on its stop timer.
If a run time is set to some value and the stop time is left set at zero, the T20 will
behave as a one-shot batch controller. On pressing the reset button or switching
the pump on, the pump will run for the set period and then shut down. It will not
then restart until you again press the reset button or reset the power to the unit. In
cyclic running mode the T20 monitors the elapsed time and displays the remaining time on its LCD screen in hours and minutes.
Cyclic running allows low yield bores to be pumped to their maximum capacity.
A bore pump running under cyclic control can be set to pump the bore down to a
low level, stop and wait for the standing water level to recover and then repeat the
process endlessly. For transfer pumping applications cyclic running can be used
to automatically top up remote tanks without the need for oat valves or level
control at the tank. It can also be used for one-shot tank lling. Press the reset
button and pump a set number of hours of water to a tank, and then stop until the
reset is again pressed.
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Anti-Cycling
Electric motors are often limited in the number of times they can be safely started
in an hour. This is particularly important in the operation of submersible bore
pumps. When a motor starts there is an initial inrush of current that produces
heat in the coils and iron rotor of the motor. If the frequency of starts is excessive
the accumulation of heat within the motor can cause severe damage and eventual failure of the motor. Submersible bore pump motors are particularly prone to
damage from excessive cycling (starting and stopping).
The anti-cycling option built into the T20 allows the user to set the maximum
number of times the pump can be safely started in any one hour period. If you
select yes to this option the screen that follows will ask you to enter the maximum
number of times the pump can be started in any one hour. The number of starts
can be set from 1 start per hour to 1800 starts per hour. Please contact your
pump supplier to obtain the correct gure for your specic pump. In operation the
anti-cycling system monitors both time and the number of starts and compares
the two. If the starts per hour rate is exceeded 10 consecutive times in any one
hour period the pump will be automatically shut down and the T20 will display a
message indicating the starts per hour rate was exceeded.
As a simple example of the way the anti-cycling system works, if the starts per
hour rate is set to 360 (one start every 10 seconds maximum) and the pump
started 9 times in a row at less than 10 seconds between each start and then
did not start again for 12 seconds the anti-cycling shutdown will not be invoked.
If however, the pump were to start 10 times in a row with less than 10 seconds
between the starts the anti-cycling system would be invoked and the pump would
be shut down.
In a conventional pressure system the anti-cycling function can be used to protect
the pump from damage in the event of the system’s air cell losing its air charge.
If air is lost from a system’s air cell due to a ruptured diaphragm or leaking air
valve, the pump will hunt on and off rapidly. Such rapid cycling will cause the
pump to overheat very quickly. The T20’s anti-cycling feature can be used to shut
down the pump and prevent damage in such a situation. To use the anti-cycling
function for this type of pump protection simply set the starts per hour to some
value that is marginally higher than the system’s normal start rate. This will avoid
nuisance tripping but will shut the pump down if excessive sequential cycling is
encountered.
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Burst Pipe Detector
The T20 timer includes a system for detecting burst pipes. It is most commonly
used in systems that are set up as a pressure system and are controlled by an
external pressure switch.
If a pressure system bursts its discharge pipe the system pressure will fall and
the pump will start at its low pressure setting. The pump will then run continuously until the water source is depleted. If the discharge pipe splits and the pump
has sufcient capacity the result may be continuous cycling of the pump as it
attempts to satisfy the leak. The T20 addresses these two scenarios with two
separate functions, anti-cycling and burst pipe detection. When both functions
are activated the complete spectrum of possibilities is covered. Anti-cycling will
detect cyclic starting and stopping and can be set to shut the pump down after a
predetermined number of cycles. This function detects split and leaking pipes.
The burst pipe detector addresses the issue of a completely burst pipe where the
pump would ordinarily discharge at its full capacity until the source of water was
depleted. It does this by using a timer that times out for a settable period each
time the pump runs. The timer resets back to its original setting each time the
pump stops. The range of adjustment is zero to 99 hours 59 minutes in increments of 1 minute.
In a typical application the burst pipe detector would be set to some time that
was marginally longer than the longest time the pump would ordinarily run. For
example, in a domestic pressure system day to day usage may require the pump
to run for no longer than 15 minutes (for showers etc.) Perhaps once every few
days the system is used for garden watering and required to run for 30 minutes.
In this scenario the burst pipe detector would be set to 35 or 40 minutes.
Each time the pump switches on the burst pipe detector begins to count down. In
normal circumstances the pump will shut off in less than 30 minutes. This resets
the burst pipe detector’s timer back to 40 minutes. If however, the pump continues to run due perhaps to a burst pipe, it will eventually reach the set point of 40
minutes. The pump will then be instantly shut down preserving whatever source
water remains. The T20 will then display “burst pipe detected” on its LCD screen.
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LCD Screen Back Light
The LCD screen on the T20 timer has a built-in backlight. The backlight switches
on automatically whenever you are programming the timer and when the T20 is
displaying certain fault conditions. In normal operation the backlight remains off.
The LCD screen backlight can be switched on manually at any time by pressing
and holding down the down arrow button. The screen will remain illuminated
while you are depressing the down button. The screen will switch off as soon as
you release the button. The LCD backlight can’t be permanently switched on, it
only operates while the down button is held in.
Program Lock
The T20 timer has a hidden security lock. When activated, the lock disables the
programming button P and prevents access to the T20’s menu.
To lock or unlock the T20, press the up and down buttons together while the pump
is in normal operation (not while it is being programmed). Pressing the up and
down buttons together while in normal running mode shuts down the pump and
opens the timer’s lock screen. Once the lock screen is displayed the timer can
be locked or unlocked by pressing the up or down buttons. Pressing P then exits
the lock screen and the timer resumes normal operation. When locked, pressing
the P button has no effect on the timer and does not take you into the menu in
the usual way. Access to the menu can then only be obtained by rst unlocking
the program.
Maintenance
The T20 timer is a low maintenance device. If it is correctly installed in a location
that is out of direct exposure to the elements it should give a long and reliable life
and require little or no maintenance at all.
Factors that may reduce its life are lightning strikes or power surges, failure to
fully tighten lid or cable glands, exposure to temperatures in excess of its ratings
and operation outside its electrical limitations in terms of supply voltage and motor loads. Spare parts are available for the T20 timer from your supplier.
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WARNING
If the T20 timer is used in a manner not speci-
ed by the manufacturer the pump protection
provided by the timer may be impaired or negated. In addition, all warranties stated or implied
will be rendered invalid.
Warranty
The T20 timer is warranted against faulty workmanship and materials for a period
of 12 months from the date of purchase. Our complete warranty statement can
be downloaded from :
http://www.kelco.com.au/menu/information/warranty-statement
If a warranty issue arrises with this product contact your supplier or Kelco Engineering Pty Ltd. You will be issued with a returns goods authorisation number.
The RGA number and proof of purchase must accompany any goods returned to
us under warranty.
Designed and Manufactured in Australia by
KELCO Engineering Pty Ltd
A.B.N. 20 002 834 844
Head Ofce and Factory: 9/9 Powells Road Brookvale 2100 Australia
Postal Address: PO Box 7485 Warringah Mall NSW 2100
Phone: +61 2 99056425 Fax: +61 2 99056420 Email: sales@kelco.com.au
Web www.kelco.com.au
PLEASE NOTE Kelco Engineering Pty Ltd reserves the right to change the specication of this
product without notice. Kelco Engineering Pty Ltd accepts no liability for personal injury or economic loss as a consequence of the use of this product. All rights reserved copyright Kelco Engineering
Pty Ltd © 2014
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