Trane 4TTM3018 Installer's Manual page 22

STEP 8 - Determine Required Refrigerant Adjustment
Compare the Measured Liquid Line Temperature from Step 6 against the Target (MINIMUM) Liquid Temperature
from Step 7.
If the Measured Liquid Line Temperature is above the Target (MINIMUM) Liquid Temperature and the Maximum
Allowable Liquid Pressure has not been exceeded, you will add charge to the system.
If the Measured Liquid Line Pressure is higher than the Maximum Allowable Liquid Pressure, you will remove
charge.
If the Measured Liquid Line Temperature is lower than the Target (MINIMUM) Liquid Temperature, you will remove
charge.
STEP 9 - Add or Remove System Charge
Add system charge
Important: Charging must be performed us-
ing the manual charge assist port for accurate
charging.
If step 8 above indicates to add charge:
1. Connect charging hose from bottle to charg-
ing port (bottle first).
2. Purge hose at bottle fitting.
3. Open bottle and turn upside down.
Note: The manual charge assist port allows you
to charge the unit using liquid.
Once the Measured Liquid Line Temperature is
within 1 to 2 ºF of the Target (MINIMUM) Liquid
Temperature, stop charging.
As the charge level in the unit increases, Suction
Pressure might increase slightly and Liquid Line
temperature will decrease.
Remove system charge
If the Measured Liquid Line Pressure is higher
than the Maximum Allowable Liquid Pressure or
if the Measured Liquid Line Temperature is lower
than the Target (MINIMUM) Liquid Temperature,
recover refrigerant from the system.
22
Manual Charge Assist Hookup
Leave bottle closed until ready to charge
18-AC78D1-6