Admonishments. Emerson M820B, M820D

User Instructions

Spec No. 1M820BNA (Model M820B)

Spec No. 1M820DNA (Model M820D)

2.7.5 Paralleling the Existing and ACU+ Power Systems

Admonishments

UM1M820BNA

Issue AH, March 4, 2013

General Safety

Danger: YOU MUST FOLLOW APPROVED SAFETY PROCEDURES.

Performing the following procedures may expose you to hazards. These procedures should be performed by qualified technicians familiar with the hazards associated with this type of equipment. These hazards may include shock, energy, and/or burns. To avoid these hazards: a) The tasks should be performed in the order indicated. b) Remove watches, rings, and other jewelry. c) Prior to contacting any uninsulated surface or termination, use a voltmeter to verify that no voltage or the expected voltage is present. d) Wear eye protection, and use recommended tools. e) Use double insulated tools appropriately rated for the work to be performed.

AC Input Voltages

Danger: This system operates from AC voltage capable of producing fatal electrical shock.

DC Input/Output Voltages

Danger: Connecting the ACU+ power system to an existing power system for “Power Split” mode involves working on live equipment carrying live loads. This system produces DC power and may require battery to be connected to it. Although the

DC voltage is not hazardously high, the rectifiers and/or battery can deliver large amounts of current. Exercise extreme caution not to inadvertently contact or have any tool inadvertently contact a battery terminal or exposed wire connected to a battery terminal. NEVER allow a metal object, such as a tool, to contact more than one termination at a time, or to simultaneously contact a termination and a grounded object. Even a momentary short circuit can cause explosion and injury.

Remove watches, rings, or other jewelry before connecting leads. Cover any live busbars with a canvas sheet to prevent short circuits caused by falling tools or parts.

Preparing the Existing and ACU+ Power Systems

Install and turn-up the ACU+ power system as describe in the installation instructions furnished with the power system.

Set the float voltage on both the existing and ACU+ power systems to the same level. Temperature compensation functionality, if used, should be disabled on both power systems.

Paralleling the Systems

Connect the Battery and Battery Return busbars of the ACU+ Power System to the main charge busbars (rectifier side of the shunt) on the parallel power system. Size the cable for the largest current between systems.

Note 1: The connections between the two power systems should be done with power cables appropriately sized to be capable of carrying the maximum current that can circulate between the two power systems.

Chapter 2. Operation 75

This document is property of Emerson Network Power, Energy Systems, North America, Inc. and contains confidential and proprietary information owned by Emerson Network Power, Energy

Systems, North America, Inc. Any copying, use, or disclosure of it without the written permission of Emerson Network Power, Energy Systems, North America, Inc. is strictly prohibited.

UM1M820BNA

Issue AH, March 4, 2013

User Instructions

Spec No. 1M820BNA (Model M820B)

Spec No. 1M820DNA (Model M820D)

Note 2: If the parallel power system incorporates a main plant shunt, the connections of the cables from the ACU+ power system to the parallel power system shall be made on the main charge busbars (rectifier side of the shunt).

Note 3: To compensate for voltage drop, it is recommended to connect the ACU+ power system’s remote sense leads (if available) to the same point of sensing as the parallel power system.

Note 4: There shall be only one battery return reference (BRR) cable for the two power systems. If the cable is appropriately sized on the parallel power system, keep it as the BRR for both power systems. If the cable is not appropriately sized on the parallel power system, install a new BRR cable and connect it preferably to the ACU+ power system since the parallel power system may eventually be phased out.

Note 5: If battery disconnect units (BDUs) are used on the new or parallel power system, these shall be wired in such a way as to be all triggered simultaneously in order to prevent any overloading of these.

Note 6: For the size and number of bridge cables between the two power systems, take into consideration the voltage drop, the available connecting points in each system, as well as the fact that these cables are unfused and shall therefore be run on a dedicated cable rack.

“C” or “H” taps may be used to make full use of available connecting points.

Note 7: The legacy system retains the function of its controller and the percent of load on each plant is controlled by the ACU+. Alarms may be sent individually from each plant, or combined using an ACU+ Interface Board and the programmable relays resident in the controller.

Note 8: Add a label on both power systems to indicate that these are operating in the Power Split

Mode with each other.

Optional Function Connections: The following signals from the existing system must be connected to digital inputs of the ACU+ system interface board for these functions to be active: Equalize Charge in Progress, Battery Test in Progress, Load LVD Active, and Battery LVD Active. Otherwise disable these functions.

76 Chapter 2. Operation

This document is property of Emerson Network Power, Energy Systems, North America, Inc. and contains confidential and proprietary information owned by Emerson Network Power, Energy

Systems, North America, Inc. Any copying, use, or disclosure of it without the written permission of Emerson Network Power, Energy Systems, North America, Inc. is strictly prohibited.