Main Exv Control - Carrier AquaForce 30XV140 Controls, Start-Up, Operation, Service And Troubleshooting Instructions

BRAZED PLATE HEAT EXCHANGER
(ECONOMIZER)
MAIN EXV
1. Cable
2. Glass Seal
3. Motor Housing
4. Stepper Motor
5. Bearing
6. Lead Screw
7. Insert
8. Valve Piston
9. Valve Seat
10. Valve Port
EXV TROUBLESHOOTING PROCEDURE — There are
two different economizer EXVs. Both of the economizer
EXVs have a total of 2625 steps. There are three different main
EXVs, which all have a total of 3810 steps. The EXV motor
moves at 150 steps per second. Commanding the valve to ei-
ther 0% or 100% will add an additional 160 steps to the move,
to ensure the valve is open or closed completely.
CAUTION
Do not remove EXV cables from the SIOB board with the
power applied to the board. Damage to the board may occur.
ECONOMIZER RELIEF
SIGHT GLASS
Fig. 47 — Economizer Assembly
Fig. 48 — Cutaway Views of the Electronic Expansion Valve
ECONOMIZER FLOW TO COMPRESSOR
ECONOMIZER EXV
FILTER DRIER
MAIN FLOW TO EVAPORATOR
Follow the steps below to diagnose and correct EXV prob-
lems. Check EXV motor operation first. Switch the Enable/
Off/Remote (EOR) Contact switch to the Off position.
Check the appropriate circuit EXV, EXV Position Circuit A
% Open (Main Menu  Quick Test  Circuit A EXV Posi-
tion) or EXV Position Circuit B % Open (Main Menu 
Maintenance Menu  EXV Control). Use Quick Test proce-
dure on page 116. The current value of 0 will be displayed. In-
crease the EXV position to select 100% valve position. The ac-
tuator should be felt moving through the EXV. To close the
valve, select 0%. The actuator should knock when it reaches
the bottom of its stroke.
53
LIQUID LINE SHUT OFF VALVE
a30-4241