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Delta UPS - Amplon Family
RT Series, Three Phase
10/ 15/ 20 kVA
Maintenance Bypass Box
for Single UPS
User Manual
www.deltapowersolutions.com

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This manual contains important instructions and warnings that you should follow during the
installation, operation, storage and maintenance of this product. Failure to heed these
instructions and warnings will void the warranty.
Copyright © 2019 by Delta Electronics Inc. All Rights Reserved. All rights of this User Manual
(“Manual”), including but not limited to the contents, information, and figures are solely owned and
reserved by Delta Electronics Inc.(“Delta”). The Manual can only be applied to the operation or the
use of this product. Any disposition, duplication, dissemination, reproduction, modification,
translation, extraction, or usage of this Manual in whole or in part is prohibited without the prior
written permission of Delta. Given that Delta will continuously improve and develop the product,
changes may be made to the information in this Manual at any time without obligation to notify any
person of such revision or changes. Delta will make all possible efforts to secure the accuracy and
the integrity of this Manual. Delta disclaims any kinds or forms of warranty, guarantee, or
undertaking, either expressly or implicitly, including but not limited to the completeness,
faultlessness, accuracy, non-infringement, merchantability or fitness for a particular purpose of the
manual.
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1

Table of Contents
1. Product Introduction ................................................................................. 3
2. Important Safety Instructions ................................................................... 4
2.1. Safety Instructions .......................................................................... 4
2.2. Standard Compliance ..................................................................... 5
2.3. Storage ............................................................................................. 5
3. Package list ................................................................................................ 6
4. The Rear Panel ........................................................................................... 8
5. Installation Procedures ........................................................................... 11
6. Connection ............................................................................................... 14
6.1. Pre-connection Warnings ............................................................. 14
6.2. The Connection with the UPS model without power cables ..... 14
6.3. Main input , Bypass Input and Output Connection of the MBB 18
6.3.1. Single Source Input & Single Phase Output .................... 24
6.3.2. Dual Source Input & Single Phase Output ....................... 25
6.3.3. Dual Source Input & Three Phase Output ........................ 26
6.3.4. Single Source Input & Three Phase Output ..................... 27
6.4. Connection of the MBB and the UPS .......................................... 28
7. Operation Procedures ............................................................................. 31
8. Maintenance Bypass ............................................................................... 32
Appendix 1 : Technical Specifications .......................................................... 35
Appendix 2 : Warranty .................................................................................... 37
2

Chapter 1 : Product Introduction
The Delta Maintenance Bypass Box (MBB) is applicable to Delta Amplon UPSs:
RT-15K3P and RT-20K3P. The MBB provides AC input power to the UPS and
connects the output of the UPS to the critical loads and is configurable for single-
phase or three-phase output to suit your needs. When your UPS needs
maintenance, you can switch on the MBB’s manual bypass switch to let the
power be transferred from the inverter output to the manual bypass output to
ensure continuous power supply to your critical loads when the UPS is under
maintenance. Product Introduction
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3

Chapter 2 : Important Safety Instructions
Important Safety Instructions
2.1. Safety Instructions
Installation Warnings
• Before installation and usage, please read this User Manual thoroughly.
This will help you to use the product correctly and safely.
• Install the MBB in a well-ventilated area, away from excess moisture, heat,
dust, flammable gas or explosives.
• To avoid fire accidents and electric shock, please install the MBB in an
indoor area free of conductive contaminants and the temperature and
humidity must be well-controlled. For the temperature and humidity
specifications, please refer to Appendix 1 : Technical Specifications.
• Leave adequate space (at least 50 cm) around all sides of the MBB for
proper ventilation.
Connection Warnings
• The MBB must be well grounded due to a possible risk of current leakage.
• The installation of upstream and downstream protective devices is highly
recommended when the MBB is connected to the UPS.
• The protective devices connected to the MBB must be installed near the
MBB and must be easily accessible for operation.
•
If you need to move the MBB or perform re-wiring, please turn off the AC
input power. Otherwise, the output end might still be energized, which might
cause electric shock.
Usage Warnings
• To ensure reliable operation of the MBB and to protect the MBB from
overheating, the slits and openings in the MBB must not be blocked or
covered.
• Before usage, you must allow the MBB to adjust to room temperature for at
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least one hour to avoid moisture condensing inside the MBB.
• Do not pour and splash any liquid on the MBB. Do not insert any object into
the MBB’s slits and openings. Do not put beverage containers on or around
the MBB.
• Do not apply any cleaning liquid or cleaning spray to the MBB. Before
cleaning, please make sure that the input power cables have been
unplugged.
• All maintenance services must be performed by qualified service personnel.
• Forbid opening or removing the cover of the MBB by yourself to avoid high
voltage electric shock.
• You must contact qualified service personnel if either of the following events
occurs:
1. Liquid is poured or splashed on the MBB.
2. The MBB does not run normally after the instructions in this User Manual
are carefully observed.
2.2. Standard Compliance
IEC/EN 62040-1
2.3. Storage
• Prior to installation
If the MBB needs to be stored prior to installation, it should be placed in a
dry area. The allowable storage temperature and relative humidity (non-
condensing) are -15°C ~ +55°C and 5 ~ 95% respectively.
• After usage
Remove all equipment from the MBB, and store the MBB in a dry and well-
ventilated area at a temperature between -15°C and +55°C and at a relative
humidity (non-condensing) between 5 ~ 95%.
5
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Chapter 3 : Package List
3. Package list
The package contains the following items shown in Figure 3-1. Please check if
any item is missing. If there is anything missing, please contact the dealer
immediately.
Model: MBB-RT-15/20K WW2U
(Figure 3-1: Package List)
No. Item Quantity
MBB 1 PC
1
User Manual 1 PC
2
MBB Communication Cable 1 PC
3
Ear Bracket Kit 1 SET
4
BUS Bar 1 SET
5
6 Cover and Screws*1
7 Power cable*
2
1 SET
1 SET
6

NOTE :
1
1. *
The cover and screws should be installed on the MBB to protect the
power cables as shown in Figure 6-12.
2. *2 There are 3 power cables: main input power cable (4 pins), bypass
input power cable (6 pins) and output power cable (6 pins). These three
power cables are for connection with the UPS model shipped without the
cables already being installed on the UPS; the connection should be
performed by qualified service personnel.
3. If there is any damage or anything missing, please immediately contact
the dealer from whom you purchased the unit.
4. If the MBB needs to be returned, carefully repack the MBB and all of
the accessories with the original packing material that came with the unit.
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4. The Rear Panel
NOTE:
1. There are no operational components or interfaces on the front of the
MBB.
2. The UPS AC input, the UPS bypass input and the UPS AC output
marked with ❷ ❸ ❹ in Figure 4-1 are originally covered, after removing
the cover, you can see them and conduct the connection. For the details
of connection, please refer to Chapter 6: Connection. Please note that
the cover should be reinstalled as the original state after you remove the
connection between the MBB and the UPS.
3. The AC input, the bypass input and the AC output marked with ❻ ❼
❽ in Figure 4-1 are covered with a knockout cover respectively. When
conducting the connection, you have to remove the knockout covers
shown in Figure 6-1. For the details of connection, please refer to Chapter
6: Connection. Please note that the knockout covers do not need to be
Chapter 4 : The Rear Panel
reinstalled.
(Figure 4-1: The Rear Panel of the MBB)
8

No. Item Function
1 MBS Port
Connect to the parallel port of UPS to
send messages.
Connect to the UPS’s AC input power
2 UPS AC Input Port
cable.
Connect with the UPS’s bypass power
3 UPS Bypass Input Port
cable.
4 UPS AC Output Port Connect with the UPS’s output socket.
No connection is needed. The function is
to switch the UPS into manual bypass
mode for maintenance without power
supply interruption.
NOTE:
There is a warning cover on the
manual bypass switch. After you
unscrew the 3 screws shown in
Manual Bypass Switch
5
(covered)
AmplonRTSeries
Figure 8-1 and remove the
warning cover, you can see the
switch and the MBB’s detector will
be automatically activated and
send a message to the UPS to
make it transfer to bypass mode.
WARNING:
Opening the warning cover will
cause inverter shutdown. Only
authorized service personnel can
open and operate it.
9

6 AC Input Terminals
7 Bypass Input Terminals
Include mL1 (VIN_R) / mL2 (VIN_S) / mL3
(VIN_T) / N (IP_N) *
1
terminals which connect
to the main AC source.
Include bL1 (BYP_R) / bL2 (BYP_S) / bL3
(BYP_T )/ N (IP_N) *
1
terminals which
connect to the bypass source.
Include L1 (VOUT_R) / L2 (VOUT_S) / L3
8 AC Output Terminals
NOTE:
*1
For dual-source input configurations, the main AC source and the
bypass source must use the same neutral (N). For the details of
connection, please refer to Chapter 6: Connection.
(VOUT_T) / N (OP_N) which connect to the
critical loads.
10

Chapter 5 : Installation Procedures
5. Installation Procedures
Please follow the steps below to conduct rack mounting:
Step ❶ : Attach the included ear brackets to the MBB and verify all screws have
been properly fastened. Please see Figure 4-1.
(Figure 5-1: Attach the Included Ear Brackets to the MBB)
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