Remote Current Limit Reset Control - York YCIV Series Installation Operation & Maintenance

Air-cooled screw liquid chillers e/v high efficiency and s/p standard efficiency

Table of Contents

FORM 201.23-NM2

ISSUE DATE: 09/25/2020

Control Board jumper JP4 must be positioned correctly

to receive either a voltage (0 VDC through 10 VDC or

2 VDC through 10 VDC) or current (0 mA through 20

mA or 4 mA through 20 mA) signal. Place the jumper

in the "V" position for a voltage signal or mA for a cur-

rent signal (See Figure 27 on page 166 and Figure 28

on page 167). The software must be configured under

the OPTIONS key for the specific type of input signal

to be used.

The maximum temperature reset is achieved at either

10 VDC or 20 mA. Sending the minimum signal (0

VDC, 2 VDC, 0 mA, or 4 mA based on the OPTIONS

key setting) causes the setpoint to revert back to its lo-

cal programmed value. If the setpoint reset causes the

setpoint to go over the maximum programmable value,

it will be set to the maximum programmable setpoint.

0 VDC through 10 VDC Reset Input

A 0 VDC signal produces a 0°F reset. A 10 VDC signal

produces the maximum remote temp reset (program-

mable under the SETPOINTS key). The setpoint reset

is ramped linearly between these limits as the input

varies between 0 VDC and 10 VDC. In order for this

input to work properly, the Remote Temperature Reset

must be programmed for 0 VDC through 10 VDC in-

put (OPTIONS key) and Chiller Control Board jumper

JP4 placed in the "V" position.

2 VDC through 10 VDC Reset Input

A 0 VDC to 2 VDC signal produces a 0°F reset. A 10

VDC signal produces the maximum remote temp re-

set (programmable under the SETPOINTS key). The

setpoint reset is ramped linearly between these limits

as the input varies between 2 VDC and 10 VDC. In

order for this input to work properly, the Remote Tem-

perature Reset must be programmed for 2 through 10

VDC input (OPTIONS key) and Chiller Control Board

jumper JP4 placed in the "V" position.

0 mA through 20 mA Reset Input

A 0 mA signal produces a 0°F reset. A 20 mA signal

produces the maximum remote temp reset (program-

mable under the SETPOINTS key). The setpoint reset

is ramped linearly between these limits as the input

varies between 0 mA and 20 mA. In order for this in-

put to work properly, the Remote Temperature Reset

must be programmed for 0 mA through 20 mA input

(OPTIONS key) and Chiller Control Board jumper JP4

placed in the "mA" position.

JOHNSON CONTROLS

4 mA through 20 mA Reset Input

A 0 mA to 4 mA signal produces a 0°F reset. A 20 mA

signal produces the maximum remote temp reset (pro-

grammable under the SETPOINTS key). The setpoint

reset is ramped linearly between these limits as the in-

put varies between 4 mA and 20 mA. In order for this

input to work properly, the Remote Temperature Reset

must be programmed for 4 mA through 20 mA input

(OPTIONS key) and Chiller Control Board jumper JP4

placed in the "mA" position.

Local Current Limit Control

Local Current Limit Control is used to set the ac-

tual Current Limit Setpoint. This is accomplished by

changing the Local Current Limit Setpoint under the

PROGRAM key. This is the value at which the unit

will begin to current limit and override capacity control

if remote reset is not actively overriding this control. If

any other current limit methods are active, the lowest

value will be used.

Keep in mind that limiting current may interfere with

capacity control, pulling down chilled liquid tempera-

tures on hot water starts, and maintaining chilled liquid

setpoints.

Pulldown Current Limit Setpoint

The Pulldown Current Limit Setpoint can be set under

the PROGRAM key. This current limit setpoint is only

active on start-up for the time defined by the Pulldown

Current Limit Time under the PROGRAM key. After

the run time has exceeded this time, the Pulldown Cur-

rent Limit Setpoint is ignored.

This control is useful in limiting current pulldown de-

mand during peak usage periods where electric costs

are highest.

Keep in mind that limiting current may interfere with

capacity control, pulling down chilled liquid tempera-

tures on hot water starts, and maintaining chilled liquid

setpoints.