Refrigerant Level Control Screen - York YD Mod D Operation Manual

Refrigerant level control screen

Figure 9: Refrigerant level control screen
This screen displays a cutaway view of the chiller condenser, along with the liquid refrigerant level
sensor and variable orifice. Setpoints relating to the liquid level control are maintained on this
screen. Through animation, the variable orifice position is displayed. Also, the refrigerant flow
control valve (variable orifice) can be manually operated. It is only accessible with a Service Level
Password.
Table 13: Display only fields
Field/LED name
Condenser refrigerant level
Subcooler effectiveness
Level control state
Startup delay remaining
Level control valve command
38
Description
Displays the present position of the liquid level. The refrigerant level is animated in the
cutaway view of the condenser. When the actual level is 0% to 15%, the level is shown
as 50% full. When the actual level is16% to 31%, the level is shown as 60% full. When
the actual level is 32% to 47%, the level is shown as 70% full. When the actual level is
48% to 63%, the level is shown as 80% full. When the actual level is 64% to 79%, the
level is shown as 90% full. Actual levels above 79%, are shown as 100% full.
Note: Requires a logon access level of Service.
The Subcooler Effectiveness is evaluated with the following calculation and compared
to a high and low limit. (Cond Sat Temp-Drop Leg Ref Temp)/(Cond Sat Temp-Entering
Cond Liq Temp). This value is typically near 0.8 at design conditions.
Indicates one of the following states the level control routine is in: Manual, Inactive,
Startup Hold, Setpoint Ramp, PID Control, Hold.
The level valve is held at the starting position until 15 seconds after start to allow the
system to stabilize. Then the valve position is controlled by the PID loop. This read box
displays the remaining seconds until PID control.
Indicates the valve command as a percentage of full open. It is only displayed when
the valve control method is analog.
Model YD Mod D with OptiView Control Center