Cascade Controller Features; Pump Status And Control; Manual Pump Control - Danfoss MCO 101 Manual

Extended and advanced cascade controller option

Table of Contents

Extended and Advanced Cascade Controller

Option

5 Cascade Controller Features

5.1.1 Introduction

Once the cascade controller has been configured, it can be enabled or disabled through parameter 27-10 "Cascade Controller." To start the cascade

controller, the master drive needs to be started as a normal drive through the LCP or through field buss communications. It will then attempt to control

the system pressure by varying the speed of the adjustable frequency drive and by staging on and off pumps as needed.

Two stop functions are provided by the cascade controller. One function quickly stops the system. The other stages off pumps in a sequence, allowing

for a pressure controlled stop. For the VLT AQUA Drive equipped with safe stop, Terminal 37 will turn off all relays and coast the master drive. If any of

the digital inputs are set to [8] "Start" and the corresponding terminal is used to control the starting and stopping of the drive, setting the terminal to 0

volts will turn off all relays and coast the master drive. Pressing the OFF button on the LCP will cause a sequenced de-staging of all the running pumps.

5.2.1 Pump Status and Control

The 27-0* group of parameters provides a convenient place to check on the status of the cascade controller and to control individual pumps. In this

parameter group, it is possible to select a specific pump to view the current status, the current running hours, and the total lifetime hours. From the same

location, an individual pump can be manually controlled for maintenance purposes.

The parameter group is organized as follows:

27-01 Status

27-02 Control

27-03 Current Hrs

27-04 Lifetime Hrs

Navigate to the 27-0* group on the LCP.

Use the right and left arrows on the LCP to select the pump.

Use the up and down arrows on the LCP to select the parameter.

5.2.2 Manual Pump Control

The extended cascade controller allows for complete control of each pump in the system. Through parameter 27-02, pumps can be individually controlled

through their selected relays. A pump can be turned on or off outside of the control of the extended cascade controller, or can be forced to alternate the

lead.

This parameter is different than other value related parameters in that selecting one of these options will cause the action to occur and then the parameter

will revert back to its default state.

The choices are as follows:

•

No Operation - Default.

•

Online - Makes the pump available to the extended cascade controller.

•

Alternate On - Forces the selected pump to be the lead pump.

•

Offline-Off - Turns the pump off and makes it unavailable for cascading.

•

Offline-On - Turns the pump on and makes it unavailable for cascading.