TIAGO

HVAC

NOTE

Make sure following conditions are fulfilled before

getting the correct gauge readings (after engine has

warmed –up

)

Engine speed

1500 rpm

A/C inlet temperature

(Ambient Temperature)

30° - 35° C (86° - 95°

Blower speed

High

Temperature Control

Full cold

Reference value be-

fore AC operation at

both high and low

pressure sides

5-8 kg/ cm

(0.5 - 0.8

MPa)

Based on the values the following conclusions can be inferred and further troubleshooting can be done.

Low Pressure side

in kg/cm

( M Pa)

High Pressure side

in kg/cm

( M Pa)

Remarks

Symptoms

Possible rea-

sons

1.5-2.5

(0.15-0.25)

14-16

(1.37-1.57)

System pressure

is normal

Normal cooling

AC system work-

ing normal

0.5-1.0

(0.05-0.1)

7-10

(0.69-0.98)

Pressure low

Insufficient cool-

ing

1. Refrigerant

quantity too

small.

2. Gas leakage.

Vacuum

5-6

(0.5-0.6)

Refrigerant fails to

circulate

No cooling expe-

rienced

Clogging of AC

cycle.

Initially 1.5-2.5

(0.15 -0.25) and

later vacuum

Initially 14-16 (

1.37-

1.57)and later

7-10

(0.69-0.98)

Moisture present

in system.

Initially works

normally but later

no cooing experi-

enced

Freezing of ex-

pansion valve due

to presence of

moisture.

4-6

(0.4-0.6)

7-10

(0.69-0.98)

Pressure on low

pressure side is

high and pressure

on high pressure

side is low.

No cooling.

Compressor De-

fective.

2.5- 3.5

( 0.25 –

0.35)

20-25

( 1.95-2.45)

System pressure

is high.

Only Insufficient

cooling.

Excessive refrig-

erant in the

system causing

insufficient con-

denser cooling.

Insufficient cool-

ing with low

pressure piping

will be hot.

Air has entered

the system.

In sufficient cool-

ing with frost or

large amount of

dew on low pres-

sure piping

TXV valve faulty.