Emerson E2 operation manual Flexible Combiner, Modular Chiller Con- trol MCC

stages have been set to High, then the fan speed should be set to High; otherwise, the fan speed should be set to Low.

If for any reason the algorithm thinks that the high speed and the low speed should both be ON, the high- speed fan should be turned ON only.

Proper fan speed should be set when there are no heat- ing or cooling stages ON, and the Fan Always On Setpoint is enabled.

11.21.12 Configuration

Set the Strategy type under application Setup under the General tab to Separate Setpoints. Enter the desired val- ues for heating and cooling stages. Cooling, heating, alarm, and miscellaneous setpoints can be edited under additional tabs. Press Control + zero (0) while the More tab is highlighted to bring up the list of additional tabs.

11.22 Flexible Combiner

The Flexible Combiner application, a new feature of

E2 versions 2.20 and above, is a highly advanced and ver- satile I/O control program used to combine multiple ana- log and digital input values using programmed equations similar to those used in spreadsheets.

A Flexible Combiner application may have up to eight analog outputs and four digital outputs, each of whose val- ues are determined by user-programmed equations that mathematically combine up to eight analog inputs and eight digital inputs. Four of the analog outputs have the ability to remember their output state over an E2 power cycle. Additionally, up to four alarms can be set up whose trigger and alarm delays are equations. Alarm type, prior- ity, and the message for each alarm are user-configurable.

Equations used to calculate output values and time delays may use mathematical combinations of any of the Flexible Combiner's analog and digital inputs, as well as numeric and named constants, operators, functions, and even rudimentary if-then logic functions. For control of digital outputs, the Flexible Combiner also supports sepa- rate equations that determine ON and OFF delays.

For E2 versions 2.40 and above, the user can set up to four alarms whose trigger and alarm delays are equations. The user may also choose the alarm type, priority, and the message for each alarm.

The Flexible Combiner may also be programmed to operate a digital output as a PWM (pulse width modula- tion) output. In this instance, the equation written for a PWM output determines its period and pulse width. A typ- ical Flexible Combiner application consists of three types of components: inputs, equations, and outputs. For more information about this application, see the Flexible Com-

biner manual (P/N 026-1620).

11.23Modular Chiller Con- trol (MCC)

The Modular Chiller Control is available for the E2 RX model controllers version 2.82 and above. In the RX- 300, a maximum of one MCC is allowed. In the RX-400, a maximum of two MCCs are allowed.

11.23.1 Overview

A Modular Chiller is made up of a single compressor connected to a brazed plate heat exchanger that provides a chilled water and glycol mixture for cooling display cases and coolers. Multiple Modular Chillers are connected together to meet the capacity requirements of the system. Modular Chillers are designed to provide cooling by paral- leling the hydronics side of the secondary system instead of the refrigeration side of the system. These units also use a water and glycol mixture as a condensing fluid for com- pressor heat of rejection. This design eliminates the long refrigerant piping runs thereby significantly reducing re- frigerant charge.

Flexible Combiner Software Overview • 11-53