HB Products HBLT-A1 User manual

Quick guide HBLT - A1 - Liquid level Transmitter (11.08.MK) 1 / 2
Quick guide
HBLT-A1
LIQUID LEVEL
TRANSMITTER
for measuring liquid level
in refrigerant vessels
Introduction and function
HBLT-A1 capacitive liquid level transmitters used to measure liquid levels in refrigerant vessels
Transmits an active 4-20 mA signal proportional to the liquid level
Electronics converts the measured change in capacitance to a signal in proportion to the level
Factory calibrated for R717 (NH3)
This ‘quick guide’ only highlights the use of the HBLT on R717 (NH3)systems!
For all other refrigerants and full documentation please review the
‘instruction manual’ available online www.hbproducts.dk/documentation.asp
Technical data
Supply voltage and load:
24 V AC/DC ±10% (50/60Hz), 1.5 W
Signal output: 4-20 mA
Liquid refrigerants:
R717 (NH3) (factory setting)
R22, R404A, R134a, R744 (CO2) and R718 (H2O)
Liquid temperature range:
-60/+120°C (-76/+248°F)
Max. working pressure:
100 bar (1450 psig)
Enclosure: IP65
Connection: 4-pole DIN plug
NOTE! When used in refrigerants with temperatures above +60°C (140°F) (e.g. heat pump applications) a
minimum calibration must be carried out after 1 week of operation. Subsequently a minimum calibration
once a year is needed (see how to do so below).
Factory setting
The HBLT comes factory calibrated for R717 (NH3), so that it will cover 4 to 20 mA throughout the rod’s whole
measuring range. (4 mA when the transmitter does not register liquid and 20 mA when the entire transmitter is
surrounded by liquid).
Setting of refrigerant
For refrigerant: R717 (NH3) it is not necessary to change the settings. The factory setting can be used.
For all other refrigerants and full documentation please review ‘instruction manual’ available online
www.hbproducts.dk/documentation.asp
Minimum calibration (0% = 4mA)
1. Apply supply voltage
2. Empty the vessel/standpipe
3. Activate the push button for about 5 sec.
Indication: Control LED lights up (ON). When ready for calibration the LED switches OFF
4. Activate the push button once.
Indication: Control LED flashed once. When green LED flashes normally the calibration is complete.
If calibration button is not activated within 10 seconds, it will automatically leave calibration mode !
NOTE!
To avoid accumulation
of oil in the stand pipe
a 10deg. slope on the
connection pipe is
recommended.
LED behind plug

Quick guide HBLT - A1 - Liquid level Transmitter (11.08.MK) 2 / 2
Installation instruction
Mount the sensor tube in a standpipe or vessel with ¾”NPT respectively 1”BSP thread connection.
When installed on ammonia systems just apply power and the transmitter is in operation.
Electrical connection
12
3
_
+
Controller
or
PLC
24V AC or DC
(50/60hz)
_
+
4
LED indication
When voltage is applied the LED will flash rapidly as
many times as it has been calibrated through its
lifetime. The current mA output is activated as soon
as the flashing sequence has changed from rapid to
slowly.
Normal operation:
At normal operation the Green LED will be flashing
slowly.
Generally the Green LED is ON every time calibration
push button is activated.
Trouble shooting
Symptom
Cause
How to detect/repair defect
No function
No supply voltage
Wrong supply voltage
Check power supply and connection
cable
It takes a long time after power up before
the 4-20 mA signal is updated
Min./Max calibration has been
carried out several times on site.
After power up the green LED
flashes rapidly as many times as it
has been calibrated through its
lifetime. First after this green LED
flashes changes to slowly the 4-20
mA is updated
4-20 mA output signal is to low
Oil has been accumulated in the
standpipe. Oil falls to the bottom
on ammonia systems
Drain oil out of standpipe. If a very
big amount of oil is present it may
be necessary to take out the sensor
rod and clean it for oil
No 4-20 mA output
Not wired correctly
Green LED continues to flash
rapidly. If correct 24 AC/DC supply:
Check polarity
4-20 mA signal does not correspond to
actual liquid level
Wrong refrigerant selected
Set correct refrigerant
No 4-20 mA output and green LED is OFF
Electronics defect
Replace HBLT electronics
4-20 mA signal does not correspond to
actual liquid level
Operator has calibrated wrongly
Fulfil a factory reset
Further information
For further information please check our website www.hbproducts.dk or send an e-mail to: [e-mail]