Opman ASX14 v07.qxd - Fieldpiece Instruments

Superheat and
Subcooling Head for
R22 and R410A
Description
The model ASX14 superheat and subcooling
accessory head measures refrigerant pressure and
temperature simultaneously. It then calculates and
displays superheat or subcooling. It has a 1/4”
industry standard fitting for actual pressure. A pipe
clamp thermocouple is included for temperature.
Select R22 or R410A. Select superheat or subcooling.Select english or metric units.
with pipe clamp
thermocouple
Model: ASX14
Use it your way
STABLE
Air
Conditioner
Superheat
and Subcooling
ON
LO BATT
R22
SH
ENGLISH
R410A
SC
METRIC
STABLE
STABLE
Air
Conditioner
Superheat
and Subcooling
R22
R410A
STABLE
STABLE
Air
Conditioner
Superheat
and Subcooling
SH or SC
Temp
Pressure
ON
LO BATT
R22
SH
ENGLISH
R410A
SC
METRIC
Air
Conditioner
Superheat
and Subcooling
Air
Conditioner
Superheat
and Subcooling
ON
LO BATT
SC
R22
SH
ENGLISH
R410A
SC
METRIC
ENGLISH
METRIC
ON
LO BATT
R22
SH
ENGLISH
R410A
SC
METRIC
SH or SC
Temp
Pressure
SH or SC
Temp
Pressure
Set
ATM
SH or SC
Temp
Pressure
SH or SC
Temp
Pressure
ON
LO BATT
SH
T/C
Cal
Set
ATM
T/C
Cal
AUTOOFF
AUTOOFF
ASX14
ASX14
Set
ATM
Set
ATM
T/C
Cal
AUTOOFF
T/C
Cal
AUTOOFF
Set
ATM
T/C
Cal
AUTOOFF
ASX14
ASX14
ASX14
OFF
2000
OPERATOR’S MANUAL
SPECIFICATIONS
Operating environment: 32ºF to 122ºF; 0ºC to
50ºC at <75%RH
Allow ~5 min. for ASX14 to come to ambient temp.
Storage environment: -4ºF to 140ºF; -20ºC to
60ºC at <80%RH with battery removed.
Battery life: 25 hours typical. No measurable
current draw when in "off" position.
Low battery indication: Red LED lights
Battery: 9V
Auto off: Approx. 15 minutes
Overloads: The ASX14 outputs 3.4V when temperature or pressure is outside of their working
range (overloaded). For ranges below
3400mVDC, the normal overload symbol will be
displayed on the meter (“OL”). For ranges
above 3400mVDC, reading displayed will be
approximately 3.4VDC.
Stated Accuracy: at 73°F ± 9°F (23°C ±5°C) ,
<90% R.H.
Temperature
Range (temperature): -40ºF to 400ºF;
-40ºC to 204ºC
Resolutions: 0.1º
Sensor type: k-type thermocouple
Pipe clamp thermocouple accuracy: ±4ºF
(±2°C) or ±0.75%, whichever is greater, -30ºF to
200ºF (-34°C to 93°C)
System accuracy: ±1ºF;±0.06ºC @ 73ºF ± 5ºF
EHDL1 AHDL1 w/ Meter
DL3
HS30
after ice water calibration (see Field calibration).
Pressure and vacuum
Working range (pressure):
0 to 500 psi; 0 to 4000 kPa
Max displayed pressure: 800psi (5500 kPa)
Working range (vacuum):
29”Hg vac. to 0; 74cmHg vac. to 0
Vacuum will show up as negative value on meter.
Resolutions: 0.1psi or kPa, 0.1”Hg or cmHg vac.
Accuracy:
0 to 200 psig, ±1 psi, 0 to 1378 kPa ±6.9 kPa;
200 to 500 psig, 0.3% ±1 psi, 1378 to 3447 kPa
0.3% ±6.9kPa
Sensor breakdown pressure: 800psi (5500 kPa)
Superheat
Range (temperature): 0ºF to 80ºF; 0ºC to 27ºC
Resolutions: 0.1º
System Accuracy: ±1ºF @ 73ºF ± 5ºF (±0.06ºC
@ 23°C ±3°C) after calibration (see Field calibration).
How to use
1. Connect to COM and Volts jack. Slide ASX14
superheat head onto Fieldpiece "stick" meter,
data logger, electronic handle or connect to
most other meters using Fieldpiece ADLS2
deluxe test leads or AHDL1 handle.
2. Set meter to mVDC range.
3. Calibrate if needed (see Field calibration)
4. Hand tighten 1/4” flare to suction line or liquid
line as close to the evaporator or condenser as
possible using an EPA approved service hose
(not included).
5. Select superheat or subcooling, refrigerant (R22
or R410A) and units (English or metric).
6. Connect the pipe clamp to the suction (superheat) or liquid (subcooling) line at least six inches from the condenser and slide it under the
insulation for best accuracy isolating the pipe
clamp from the ambient air (pg. 2).
7. Select parameter to display (superheat, subcooling, pressure, or temperature).
8. You must wait until the system you are testing
has stabilized. The STABLE LED lights when
the reading is stable.
9. Disable Auto-off to data log any of the above
parameters with the DL3 data logger.
10. Once you have the superheat or subcooling
reading follow the manufacturer of the air conditioner’s specifications to properly charge or
diagnose the system.
Field calibration
Temperature: To calibrate the system (ASX14,
pipe clamp thermocouple, meter), adjust the calibration pot underneath the rubber covering while
measuring a known temperature. Ice water is 32°F
(0°C) and is readily available.
1. Stabilize (by repeated stirring) a large cup of ice
water.
2. Select temperature on ASX14, plug in the pipe
clamp thermocouple and then immerse entire
clamp into the ice water (keep stirring).
3. Adjust the calibration pot to read 32.0 (0.0 if
using °C) on the DMM for optimum accuracy at
room temp.
Pressure: The pressure/vacuum reading prior to
connecting to an A/C system should always be
zero. If you see that you’re getting pressure readings of something other than zero without your service hose attached, you need to set atmospheric
pressure before connecting the ASX14 to the system. To set atmospheric pressure, press the button
underneath the rubber covering entitled “Set ATM”.
You usually have to set atmospheric pressure each
time you dramatically change elevations. For example, if you “Set ATM” in Denver and take a pressure
reading of an A/C system in Los Angeles, the pressure reading in Los Angeles will be lower than it
actually is.
Warranty
The ASX14, Superheat and Subcooling accessory head is warranted against manufacturer’s defects
for one year. This warranty does not apply to
defects resulting from abuse, neglect, accident,
unauthorized repair, alteration, or unreasonable use
of the instrument. Any implied warranty arising out
of the sale of Fieldpiece's products including but not
limited to implied warranties of merchantability, and
fitness for purpose, are limited to the above.
Fieldpiece shall not be liable for incidental or consequential damages.
.
Service
Return any defective ASX14 to Fieldpiece for
warranty service along with proof of purchase.
Contact Fieldpiece for out of warranty repair
charges.
Subcooling
Range (temperature): 0ºF to 80ºF; 0ºC to 27ºC
Resolutions: 0.1º
System Accuracy: ±1ºF @ 73ºF ± 5ºF (±0.06ºC
@ 23°C ±3°C) after calibration (see Field calibration).
v07
head for both indoor wet bulb and outdoor dry bulb.
Or you can use any Fieldpiece meter that has a
temperature function along with a ATWB1 wet bulb
thermocouple. Below is a diagram of the ASX14 on
a split-system residential A/C unit.
Checking
Subcooling
Using the
ASX14
In
do
o
r
Throttle Valve (TXV, Cap tube, Fixed Oriffice)
STABLE
Air
Conditioner
Superheat
and Subcooling
ON
LO BATT
R22
SH
R410A
SC
ENGLISH
METRIC
Fl
Liquid
igerant
Condenser
ow
Fl
Vapor and Liquid
igerant
Liquid
ASX14
Evaporator
Re
fr
AUTOOFF
ut
si
T/C
Cal
O
Set
ATM
de
SH or SC
Temp
Pressure
Re
fr
Vapor and Liquid
Vapor
In
do
o
r
Vapor
ut
si
Heed all equipment manufacturer’s specifications, warnings and suggestions above anything
found in this manual.
To determine the target superheat (fixed orifice
system) or subcooling (charts vary dramatically
from one system to another), you will typically need
three things. Outdoor dry bulb (outdoor air temperature), indoor wet bulb, and the manufacturers target superheat chart or subcooling chart.
You can use the ARH4 Fieldpiece accessory
de
Target superheat and subcooling
O
Superheat is the difference between the actual
temperature of the refrigerant (gas) as it leaves the
evaporator and the boiling point temperature of the
refrigerant in the evaporator coil. After boiling, the
refrigerant continues to warm up. The number of
degrees it “warmed up” after boiling is called the
superheat. Under worst case conditions (low load
for fixed orifice systems), the refrigerant in the evaporator boils off near the end of the evaporator coil.
To make sure liquid doesn’t enter the compressor
under the worst case condition (low load), the AC
manufacturers publish charts indicating what the
superheat should be at a given indoor wet bulb
measurement and outdoor air temperature.
Measuring superheat is your best indication on a
fixed orifice system of the proper refrigerant charge
and operating conditions. If everything else is working properly and the actual superheat is too high,
add refrigerant. If it’s too low, remove refrigerant.
Subcooling is the difference between the boiling
point of the refrigerant in the condenser and the
actual temperature of the refrigerant as it leaves
the condenser. The degrees that the refrigerant
“cools down” below the boiling point is the subcooling. Under worst case scenario (low load for
TXV) the subcooling will continue to rise. If the
subcooling rises to high, liquid may be backed into
the compressor causing damage and catastrophic
failure.
On TXV systems, subcooling is the best indication of the state of charge in the refrigerant system
since these systems are designed to maintain constant superheat.
Properly charging a system ensures maximum
efficiency and longer equipment life.
The hose must have a schraeder valve depresser on one end to release the refrigerant from the
suction or liquid line. This is the same type of hose
available with most pressure gauge sets. We suggest EPA sanctioned “no leak” hoses.
Exercise caution whenever working with any
electricity and high pressure liquid or gas. Follow all
instructions provided with equipment being serviced
or installed.
ow
Measuring actual superheat and
subcooling
Compressor
STABLE
Air
Conditioner
Superheat
and Subcooling
ON
LO BATT
R22
SH
R410A
SC
ENGLISH
METRIC
SH or SC
Temp
Pressure
Set
ATM
T/C
Cal
Checking
Superheat
Using the
ASX14
AUTOOFF
ASX14
Generic Target Superheat Charts*
*
These charts are an example of a generic
superheat charts for a typical fixed orifice, split residential system. These charts should not be used
for charging. A typical manufacturer’s recommended subcooling is 12°F (7°C). These are only examples of what the manufacturer’s may recommend.
Heed all manufacturer’s indications, instructions
and warnings above those in this manual.
The indoor wet bulb measurement can be
accomplished by a Fieldpiece ARH4 or ATWB1 and
should be taken as close to the evaporator coil inlet
as possible. The outdoor dry bulb reading can be
taken with an ARH4, ATB1, ATA1 or any other
Fieldpiece air thermocouple and should be taken as
close to the condenser air inlet as possible.