CVHE-SB-32A 90
External Current Limit Setpoint
External Current Limit is an option that allows the customer to change the current limit
setpoint from a remote location. The External Current Limit Setpoint is found on Options
module terminals J7-11 and J7-12.
UCP2 accepts either a 2-10 VDC or 4-20 mA analog input to set the chillers external current
limit setpoint. 2-10 VDC and 4-20mA each correspond to a 40 to 120% RLA range.
The following equations are what UCP2 uses:
The following graph shows External Current Limit Setpoint with a 2-10 VDC input:
Voltage Signal Current Signal
As generated from external source VDC=.10*(%)-2.0 mA=.20(%)-4.0
As processed by UCP2 %=10.0*(VDC)+20.0 %=5.0(mA)+20.0
40
50
60
70
80
90
100
110
120
2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10
Volts DC
% RLA
% RLA