Fieldpiece ASH3 Operator's Manual

a

aaa

a

a

aaa

a

a

a

a

a

a

a

aaa

a

a

aaa

a

a

a

a

a

a

Fieldpiece

ASH3
Superheat Head
R22 and R410A

with thermocouple

OPERATOR’S MANUAL

Description

The model ASH3 superheat accessory head
measures refrigerant pressure and temperature
simultaneously. It then calculates and displays
superheat. It has a 1/4” industry standard fitting for
actual pressure. A pipe clamp thermocouple is
included for temperature. Select R22 or R410A.
Select english or metric units.

Use it your way

EHDL1 AHDL1 w/ Meter DL2 HS30

How to use

1. Connect to COM and Volts jack. Slide ASH3
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 as close to
the evaporator as possible using an EPA
approved service hose (not included).

5. Select refrigerant (R22 or R410A) and units
(English or metric).

6. Connect the pipe clamp to the suction line at
least six inches from the compressor 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, pres­sure, or temperature).

8. You must wait until the system you are testing
has stabilized completely before you can take
an accurate superheat reading, this usually
takes about 10-15 minutes. The STABLE LED
lights when superheat is stable.

9. Disable Auto-off to data log any of the above
parameters with the DL2 data logger.

10. Once you have the superheat reading follow
the manufacturer of the air conditioner’s specifi­cations to properly charge or diagnose the sys­tem.

Field calibration

Temperature: To calibrate the system (ASH3, pipe

clamp thermocouple, meter), adjust the calibra­tion pot underneath the rubber covering while
measuring a known temperature. Ice water is
very close to 32°F and is readily available.

1. Stabilize a large cup of ice water.

2. Select temperature on ASH3, plug in the pipe
clamp thermocouple and then immerse entire
clamp into the ice water.

3. Adjust the calibration pot to read 31.3 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
ASH3 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.

SPECIFICATIONS

Operating environment: 32ºF to 122ºF; 0ºC to

50ºC at <75%RH

Allow ~5 min. for ASH3 to come to ambient temp.

Storage environment: -4ºF to 140ºF; 0ºC to 50ºC

at <80%RH with battery removed from meter.

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 ASH3 outputs 3.4V when temper-

ature or pressure is outside of their working
range (overloaded). For ranges below
3400mVDC, the normal overload symbol will be
displayed on the meter (“OL” or depending in
the meter). For ranges above 3400mVDC, read­ing displayed will be approximately 3.4VDC.

Pressure and vacuum

Working range (pressure):

0 to 500 psi; 0 to 4000 kPa

Maximum displayed pressure: 800psi
Working range (vacuum):

29”Hg vac. to 0; 74cmHg vac. to 0

Vacuum will show up as negative value on meter.

Resolutions: 0.1psi, 0.1”Hg vac.
Accuracy:

@ 50°F to 115ºF ambient, ±1 psi, ±6.9 kPa
@ 32ºF to 122ºF ambient, ±2 psi, ±13.8 kPa

Sensor breakdown pressure: 1300psi

Temperature

Range (temperature): -40ºF to 400ºF;

-40ºC to 204ºC

Resolutions: 0.1º
Sensor type: k-type thermocouple
Pipe clamp thermocouple accuracy: ±4ºF or

±0.75%, whichever is greater, -30ºF to 200ºF

System accuracy: ±1ºF; ±0.06ºC @ 73ºF ± 5ºF

after ice water calibration (see Field calibration).

Superheat

Range (temperature): 0ºF to 80ºF; 0ºC to 27ºC
Resolutions: 0.1º
System Accuracy: ±1ºF; ±0.06ºC @ 73ºF ± 5ºF

after calibration (see Field calibration).

One year limited warranty

This head is warranted to the original purchaser
against defects in material and workmanship for a
period of one year from the date of purchase.
During the warranty period, Fieldpiece will replace
or repair the defective unit, subject to verification of
the defect.

Any damage to the sensor from dirt, mechanical
abuse, or overexposure to damaging chemicals,
including overexposure to carbon monoxide, are
not covered under this warranty. Also not covered
are defects resulting from abuse, neglect, accident,
unauthorized repair, alteration, or unreasonable
use.

ANY IMPLIED WARRANTIES ARISING OUTOF
THE SALE OF A FIELDPIECE INSTRUMENT
PRODUCT, INCLUDING BUT NOT LIMITED TO
IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE,
ARE LIMITED TO THE ABOVE. FIELDPIECE
SHALL NOT BE LIABLE FOR LOSS OF USE OF
THE INSTRUMENT OR OTHER INCIDENTAL OR
CONSEQUENTIAL DAMAGES, EXPENSES, OR
ECONOMIC LOSS, OR FOR ANY CLAIM OR
CLAIMS FOR SUCH DAMAGE, EXPENSES, OR
ECONOMIC LOSS.

Local laws vary. Above limitations or exclusions
may not apply to you. This warranty gives you spe­cific legal rights, and you may also have other rights
which vary by location.

Obtaining service

Check the battery, then call Fieldpiece for an

RMA# and send freight prepaid to Fieldpiece.

For warranty service, include proof of purchase
date. For out of warranty service, include a check or
money order for $65 (ASH3 head), or $30 (ATC1
pipe clamp thermocouple). We will pay for the ship­ping to you using the same method (ground, air,
next day, etc.) used to ship product to us.

Fieldpiece Instruments, Inc.

580 West Central Ave. Suite A

Brea, CA 92821

Phone: [phone] Fax: [phone]

www.fieldpiece.com

This chart is an example of superheat charging
charts that are supplied by A/C manufacturers with
each fixed orifice air conditioner. Note that you must
measure indoor wet bulb and outdoor dry bulb to be
able to determine the target superheat. For wet bulb
measurements, you can use Fieldpiece ARH4 rela­tive humidity head or the Fieldpiece ATWB1 wet
bulb thermocouple.

Although this chart may be similar to many charts
supplied by manufacturers, you should use the
chart supplied by the manufacturer of the air condi­tioning equipment. Fieldpiece bears no responsibil­ity of results in using this chart.

Generic Target Superheat Chart (for fixed orifice systems) *

Measuring actual superheat

Superheat is the difference between the boiling
point temperature of the refrigerant in the evapora­tor coil and the actual temperature of the refrigerant
(gas) as it leaves the evaporator. 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),
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 opperating conditions. If everything else is
working properly and the actual superheat is too
high, add refrigerant. If it’s too low, remove refriger­ant.

Using superheat to determine proper charge
enables an air conditioner to deliver the maximum
cooling power, the best reliability, and the best effi­ciency.

The ASH3 should only be connected to the low
pressure side of an A/C refrigerant circuit.

The hose must have a schraeder depresser on
one end to release the refrigerant from the suction
line. This is the same type of hose available with
most pressure gauge sets. We suggest EPAsanc­tioned “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.

Target superheat

To determine the target superheat, you will need
three things. Outdoor dry bulb (outdoor air temper­ature), indoor wet bulb, and the manufacturers tar­get superheat chart.

You can use the ARH4 Fieldpiece acessory 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 A TWB1 wet bulb ther­mocouple.

Set up for the ASH3

(meter not shown)

A: Compressor
B: Service port
C: Pipe clamp thermocouple

connected to suction

line under insulation
D: Suction line
E: Evaporator

AUTO-

OFF

T/C

Cal

STABLE

Pressure

Temp

Superheat

ON

LOBATT

Superheat
Accessory
Head

ENGLISH

METRIC

R22

R410A

Set

ATM

ASH3

A

C

B

D

E

*