Delta NT Series User manual

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Delta UPS - Ultron Family
User Manual
The power behind competitiveness
NT Series, Three Phase
10-500 kVA

II
Ultron NT Series
Save This Manual
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 © 2018 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,
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Table of Contents
III
Table of Contents
Chapter 1 : Important Safety Instructions ------------------------------- 1
Chapter 2 : Introduction ------------------------------------------------------- 3
Chapter 3 : Operation Modes ------------------------------------------------ 4
3.1 Normal Mode (Single) --------------------------------------------- 4
3.2 Back-up Mode (Single) -------------------------------------------- 5
3.3 Reserve AC Supply Mode (Single) ----------------------------- 6
3.4 Maintenance Bypass Mode (single) ---------------------------- 7
3.5 ECO Mode (only for Single Unit) -------------------------------- 8
3.6 Normal Mode (Parallel) -------------------------------------------- 9
3.7 Back-up Mode (Parallel) -----------------------------------------10
3.8 Reserve AC Supply Mode (Parallel) --------------------------11
3.9 Maintenance Bypass Mode (Parallel) ------------------------13
3.10 Hot Standby Redundancy ---------------------------------------14
3.11 Common Battery ---------------------------------------------------15
3.12 Dry Contacts --------------------------------------------------------17
Chapter 4 : Installation & Wiring -------------------------------------------19
4.1 UPS Mechanism Data --------------------------------------------19
4.2 External Battery Cabinet -----------------------------------------26
4.3 External & Internal Views ----------------------------------------27
4.3.1 10~80kVA --------------------------------------------------------------------27
4.3.2 100~120kVA -----------------------------------------------------------------29
4.3.3 100kVA (Input: 480Vac; Bypass: 208/ 120Vac; Output: 208/
120Vac) -----------------------------------------------------------------------31
4.3.4 160~200kVA -----------------------------------------------------------------33
4.3.5 260~400kVA -----------------------------------------------------------------35
4.3.6 500kVA ------------------------------------------------------------------------37
4.4 Installation Environment and Safety Precaution ----------38

IV
Ultron NT Series
4.5 Electrical Connection Precaution ------------------------------39
4.5.1 Wiring Precaution ----------------------------------------------------------39
4.5.2 NT-series 500kVA Installation and Wiring ----------------------------40
4.6 UPS Installation Checklist --------------------------------------48
4.7 Floor Weight Loading Table -------------------------------------49
4.8 Cable Selection-----------------------------------------------------50
4.9 Electrical Connections --------------------------------------------52
4.9.1 10~30kVA Output 220Vac Terminal Wiring Diagram --------------52
4.9.2 10~60kVA Output 220/ 380Vac Terminal Wiring Diagram -------53
4.9.3 80kVA Output 220/ 380Vac Terminal Wiring Diagram -------------54
4.9.4 100kVA Output 220/ 380Vac Terminal Wiring Diagram ----------55
4.9.5 100kVA Output 208/ 120Vac Terminal Wiring Diagram
(Only for Dual Input Application) ----------------------------------------56
4.9.6 120kVA Output 220/ 380Vac Terminal Wiring Diagram ---------57
4.9.7 160/ 200kVA Output 220/ 380Vac Terminal Wiring Diagram ---58
4.9.8 260/ 400kVA Output 220/ 380Vac Terminal Wiring Diagram ---59
4.9.9 500kVA Output 220/ 380Vac Terminal Wiring Diagram ----------60
4.9.10 UPS Parallel Wiring Diagram (Single Input) -------------------------61
4.9.11 UPS Parallel Wiring Diagram (Dual Input) ---------------------------62
4.10 Communication Interfaces (NT-Q Board) --------------------63
4.11 Dry Contact Wiring Diagram (Default Value)----------------64
4.12 RS-485 Pin Assignment ------------------------------------------64
Chapter 5 : External Battery Cabinet -------------------------------------65
5.1 External Battery Cabinet Usage Warnings ------------------65
Chapter 6 : UPS Display and Settings -----------------------------------67
6.1 Control Panel -------------------------------------------------------67
6.2 LCD Display Screen-----------------------------------------------68
Chapter 7 : UPS Operation --------------------------------------------------87
 3UH6WDUWXS3UH7XUQRႇ:DUQLQJV ------------------------87

Table of Contents
V
7.2 Start-up Procedures ----------------------------------------------87
7.2.1 Normal Mode Start-up Procedures (Single) -------------------------87
7.2.2 Battery Mode Start-up Procedures (Single) -------------------------88
7.2.3 Manual Bypass Mode Start-up Procedures (Single) --------------88
7.2.4 ECO Mode Start-up Procedures (Single)_ only Applicable
to Single Unit with Capacity above 260kVA (Included) -----------90
7.2.5 Normal Mode Start-up Procedures (Parallel) -----------------------91
7.2.6 Battery Mode Start-up Procedures (Parallel) ------------------------92
7.2.7 Manual Bypass Mode Start-up Procedures (Parallel) ------------93
 7XUQRႇ3URFHGXUHV -----------------------------------------------96
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to Single Unit with Capacity above 260kVA (Included) -----------97
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Chapter 8 : Optional Accessories ---------------------------------------100
 SXOVH5HFWL¿HU ------------------------------------------------ 100
8.2 Input Harmonic Filter -------------------------------------------- 100
8.3 Remote Monitor ------------------------------------------------- 101
8.4 Monitoring Software -------------------------------------------- 101
8.5 Battery Start-up--------------------------------------------------- 101
8.6 ECO Mode ------------------------------------------------------- 101
$SSHQGL[7HFKQLFDO6SHFL¿FDWLRQV -------------------------------- 102
Appendix 2 : Warranty ------------------------------------------------------104

1
Ultron NT Series
Chapter 1 : Important Safety Instructions

z This manual contains important instructions that should be followed during in-
stallation and maintenance of the UPS and batteries. Before wiring and opera-
tion, read all instructions thoroughly.

z,QVWDOOWKH836LQDZHOOYHQWLODWHGDUHDDZD\IURPÀDPPDEOHOLTXLGDQGJDV
Do not let the unit come in contact with water. The UPS is only suitable for being
installed on the concrete and non-combustible surface.

z The external slits and openings in the UPS are provided for ventilation. To en-
sure reliable operation of the UPS and to protect the UPS from overheating,
these slits and openings must not be blocked or covered. Do not insert any ob-
ject into the slits and openings that may hinder ventilation.

z Do not put beverages on the UPS, battery cabinet or any other accessory asso-
ciated with the UPS.

z The UPS is designed to power modern computer loads and associated periph-
HUDOGHYLFHVVXFKDVPRQLWRUVPRGHPVFDUWULGJHWDSHGULYHVH[WHUQDOÀRSS\
drives, etc. Do not connect (1) inductive loads, (2) capacitive loads or (3) life
VXSSRUWHTXLSPHQWWRWKH836

z$OOPDLQWHQDQFHDQGLQVWDOODWLRQVKRXOGEHSHUIRUPHGE\TXDOL¿HGVHUYLFHSHU-
sonnel. The UPS contains high voltage which is potentially hazardous.

z The risk of dangerous high voltage is possible when batteries are still connected
to the UPS even though the UPS is disconnected from AC power sources. Be-
IRUHPDLQWHQDQFHSOHDVHWXUQRႇWKHH[WHUQDOEDWWHU\FDELQHW¶VFLUFXLWEUHDNHUWR
FXWRႇWKHEDWWHU\SRZHUIURPWKH836

z Isolate the UPS before working on the circuit. A readily accessible disconnect
device shall be installed.

z Before applying electrical power to the UPS, make sure the UPS is grounded to
avoid a possible risk of current leakage.

z The protective device shall be a four-pole device and shall disconnect all line
conductors and the neutral conductor.

z'RQRWGLVSRVHRIWKHEDWWHU\RUEDWWHULHVLQD¿UH7KHEDWWHULHVPD\H[SORGH

zDo not open or damage the battery or batteries. The released electrolyte is
harmful to the skin and eyes and may be toxic.

Chapter 1 Important Safety Instructions
2

zA battery can present a risk of electric shock and high short-circuit current. The
following precautions should be observed before replacement of batteries:
1. Remove watches, rings, or other metal objects.
2. Use tools with insulated handles.
3. Wear insulating gloves and boots.
4. Do not lay tools or metal parts on the top of batteries.
5. Disconnect the charging source prior to connecting or disconnecting the
EDWWHULHV¶WHUPLQDOV
WARNING:
This is a class-A UPS. In a domestic environment, the product may
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take additional measures.

zStandard Compliance:
- EN 62040-1
- EN 62040-2
- IEC 61000-4-2 Level 4
- IEC 61000-4-3 Level 3
- IEC 61000-4-4 Level 4
- IEC 61000-4-5 Level 4
- IEC 61000-4-6

z Symbol Introduction
Protective grounding terminal: a terminal which must be connected
to earth ground prior to making any other connection to the
HTXLSPHQW
A terminal to which or from which a direct current or voltage may be
applied or supplied.
This symbol indicates the word "phase".

3
Ultron NT Series
Chapter 2 : Introduction
The NT series UPS is a dedicated design for large scales of power systems such
as data centers, communication systems, satellite systems, network rooms, medical
devices, monitoring, safety and emergency systems as well as factory facilities.
7KH836DGRSWVKLJKIUHTXHQF\63:06LQXVRLGDO3XOVH:LGWK0RGXODWLRQ
inverter technology. The inverter uses an advanced IGBT module capable to
reduce the MTTR (Mean Time to Repair) and easier to be maintained, came with
DGYDQWDJHVLQKLJKHႈFLHQF\ORZWKHUPDOORVVORZQRLVHVPDOOYROXPHDQGORQJ
product life expectation. The applied MCU simplifies complicated control circuits
and reduces number of components. To improve reliability, the NT series UPS is
designed with the following two functions:
Hot standby redundancy: dual input application.
Parallel redundancy: no need to add external parallel control cards and capable to
parallel up to 8 UPS units.
The LCD display with multi-language graphical interface makes the user easier to
operate. System block diagram and status are also available on the LCD providing
the user with clear operating modes and overall conditions. The user can also
implement long-distance monitoring via various communication ports, computers
and network systems. As a result, direct monitoring and control of the UPS is
available (all messages on the LCD are generated by MCU). With the installation of
WKHSURYLGHGH[FOXVLYHVRIWZDUH836HQWU\DWRWDORI836XQLWV¶VWDWXVFDQ
be monitored at the same time via only one PC, which greatly reduces manpower
and facilitates centralized control. The circuit boards of the NT Series UPS are
interchangeable which minimizes component inventory management, and the
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DQGHQKDQFHVWKHXQLW¶VDYDLODELOLW\DQGUHOLDELOLW\

4
Chapter 3 Operation Modes
Chapter 3 : Operation Modes
There are four basic operation modes for the NT series UPS, either of which can
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operation modes are described as follows.
3.1 Normal Mode (Single)
Figure 3-1-a: Status Block of Normal Mode (10-200kVA)
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
Power Flow
BATTERY BANK
Power Flow
LOAD
STATIC SWITCHINVERTERRECTIFIER
Power Flow
Power Flow
Figure 3-1-b: Status Block of Normal Mode (260-500kVA)
MANUAL BYPASS
RESERVE INPUT
OUTPUT
STATIC SWITCH
RECTIFIER INPUT
LOAD
BATTERY BANK
SWITCH
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power FlowPower Flow
Power Flow
Power Flow
In normal mode, DC power, rectifying from AC input power, charges batteries and
powers the inverter that transforms DC power to stable and clean AC power to the
loads (see Figure 3-1-a and Figure 3-1-b).

5
Ultron NT Series
3.2 Back-up Mode (Single)
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
BATTERY BANK
Power Flow
Power Flow
LOAD
STATIC SWITCHINVERTERRECTIFIER
Power Flow
Figure 3-2-a: Status Block of Back-up Mode (10-200kVA)
MANUAL BYPASS
RESERVE INPUT
OUTPUT
STATIC SWITCH
RECTIFIER INPUT
LOAD
BATTERY BANK
SWITCH
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power FlowPower Flow
Power Flow
Figure 3-2-b: Status Block of Back-up Mode (260-500kVA)
When the utility AC power fails or unstable voltage occurs, the batteries will instantly
provide DC power to keep continuous operation. Hence, the UPS output will not be
interrupted.

6
Chapter 3 Operation Modes
3.3 Reserve AC Supply Mode (Single)
RECTIFIER INPUT
RESERVE
MAINS
BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
BATTERY BANK
Power Flow
LOAD
STATIC SWITCHINVERTERRECTIFIER
Power Flow
Power Flow
Power Flow
Figure 3-3-a: Status Block of Reserve AC Power Supply Mode (10-200kVA)
MANUAL BYPASS
RESERVE INPUT
OUTPUT
STATIC SWITCH
RECTIFIER INPUT
LOAD
BATTERY BANK
SWITCH
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flo wPowe r Flow
Power Flo w
Power Flow
Figure 3-3-b: Status Block of Reserve AC Power Supply Mode (260-500kVA)
When the inverter encounters abnormal situations such as over temperature, long-
time overload, output short circuit, abnormal output voltage and exhausted battery,
the inverter will automatically shut down itself for self-protection. Meanwhile, if the
reserve AC power is normal, the static switch will switch to the reserve AC power
to supply power to the loads without any interruption of power supply. After the
abnormal situations mentioned above are eliminated, the static switch will switch
back to the main AC source (see Figure 3-3-a and 3-3-b).

7
Ultron NT Series
3.4 Maintenance Bypass Mode (single)
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
BATTERY BANK
Power Flow
LOAD
STATIC SWITCHINVERTERRECTIFIER
Power Flow
Power Flow
Figure 3-4-a: Status Block of Maintenance Bypass Mode (10-200kVA)
MANUAL BYPASS
RESERVE INPUT
OUTPUT
STATIC SWITCH
RECTIFIER INPUT
LOAD
BATTERY BANK
SWITCH
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flow
Power Flow
Power Flow
Figure 3-4-b: Status Block of Maintenance Bypass Mode (260-500kVA)
When maintenance is needed and the reserve AC power is normal, the UPS can
be switched from inverter mode to bypass mode manually with continuous power
delivering to the loads. Under such conditions, the internal power will be completely
FXWRႇH[FHSWWKDWWKHWHUPLQDOVDQGPDQXDOE\SDVVEUHDNHURUVZLWFKVWLOOKDYHKLJK
voltage. As a result, risks will not exist in the UPS so service personnel can perform
maintenance safely (see Figure 3-4-a and 3-4-b).
NOTE :
If only single input power is available, please utilize the same power
VRXUFHIRUUHVHUYH$&LQSXWDQGUHFWL¿HULQSXW

8
Chapter 3 Operation Modes
3.5 ECO Mode (only for Single Unit)
STATIC SWITCH
OUTPUT
BREAKER/
SWITCH
LOAD
MANUAL BYPASS
BREAKER/ SWITCH
RESERVE INPUT
BREAKER/ SWITCH
RECTIFIER INPUT
BREAKER/ SWITCH RECTIFIER INVERTER
BATTERY BANK
RESERVE
MAINS
Power Flow
Power Flow
Power Flow Power Flow
Figure 3-5: Status Block of ECO Mode (10-500kVA)
In ECO mode, it is the reserve AC power to supply power to the connected loads via
the reserve input breaker or switch, static switch and the output breaker or switch.
,QWKLVPRGHWKHLQYHUWHUDIWHUUHDFKLQJWRWKHVSHFL¿HGUDWHGYROWDJHZLOOWUDQVIHU
to standby status. (1) If the reserve AC power is abnormal, the UPS will transfer to
run in normal mode. (2) If the main AC and reserve AC sources are both abnormal,
the UPS will run in battery mode. After the main AC source is recovered to normal
VWDEOHVWDWXVWKH836ZLOOUXQLQQRUPDOPRGH¿UVWDQGWKHQWUDQVIHUWRUXQLQ(&2
mode after 40 seconds.
NOTE:
ECO mode is only applicable to the UPS with capacity above 260kVA
(included). For the capacity below 200kVA (included), the function of ECO
mode is optional. Please note that ECO mode is not applicable to parallel
applications.

9
Ultron NT Series
3.6 Normal Mode (Parallel)
Figure 3-6-a: Parallel Status Block of Normal Mode (10-200kVA)
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
Power Flow
BATTERY BANK
Power Flow
STATIC SWITCHINVERTERRECTIFIER
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
Power Flow
BATTERY BANK
Power Flow
STATIC SWITCH
INVERTERRECTIFIER
Power Flow
LOAD
UPS 1
UPS 2
Power Flow
Power Flow
Power Flow
Power Flow
Figure 3-6-b: Parallel Status Block of Normal Mode (260-500kVA)
MANUAL BYPASS
RESERVE INPUT
OUTPUT
STATIC SWITCH
RECTIFIER INPUT
LOAD
BATTERY BANK
SWITCH
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flow
Power Flow
Power Flow
Power Flow
MANUAL BYPASS
RESERVE INPUT
RECTIFIER INPUT
BATTERY BANK
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flow
Power Flow
UPS1
UPS2
Power Flow
OUTPUT
STATIC SWITCH SWITCH
Power Flow
Power Flow

10
Chapter 3 Operation Modes
7ZRRUPRUH836XQLWVRSHUDWLQJLQSDUDOOHOPRGHKDYHWRVDWLVI\UHTXLUHPHQWVRI
WKHVDPHFDSDFLW\RXWSXWYROWDJHIUHTXHQF\DQGHTXDOORDGVKDUH,IRQHRIWKH
units fails and its loads are less than the sum of rated-load values of other units in
parallel, the rest of units can share the sum of loads; otherwise, all UPS units will
shut down inverters and switch to the reserve AC power to supply power to the
loads (see Figure 3-6-a and 3-6-b).
3.7 Back-up Mode (Parallel)
Figure 3-7-a: Parallel Status Block of Back-up Mode (10-200kVA)
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
Power Flow
BATTERY BANK
Power Flow
STATIC SWITCHINVERTERRECTIFIER
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
BATTERY BANK
Power Flow
STATIC SWITCHINVERTERRECTIFIER
Power Flow
LOAD
UPS 1
UPS 2
Power Flow
Power Flow
Power Flow
When the utility AC power fails or other unstable voltage occurs, the batteries will
instantly provide the inverter with DC power to keep continuous operation. Hence,
the UPS output will not be interrupted (see Figure 3-7-a and 3-7-b).

11
Ultron NT Series
Figure 3-7-b: Parallel Status Block of Back-up Mode (260-500kVA)
MANUAL BYPASS
RESERVE INPUT
OUTPUT
STATIC SWITCH
RECTIFIER INPUT
LOAD
BATTERY BANK
SWITCH
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flow
Power Flow
Power Flow
MANUAL BYPASS
RESERVE INPUT
RECTIFIER INPUT
BATTERY BANK
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flow
UPS1
UPS2
Power Flow
OUTPUT
STATIC SWITCH SWITCH
Power Flow
Power Flow
3.8 Reserve AC Supply Mode (Parallel)
Figure 3-8-a: Parallel Status Block of Reserve AC Power Supply Mode (10-200kVA)
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
Power Flow
BATTERY BANK
Power Flow
STATIC SWITCHINVERTERRECTIFIER
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
BATTERY BANK
Power Flow
STATIC SWITCHINVERTERRECTIFIER
Power Flow
LOAD
UPS 1
UPS 2
Power Flow
Power Flow
Power Flow
Power Flow
Power Flow

12
Chapter 3 Operation Modes
Figure 3-8-b: Parallel Status Block of Reserve AC Power Supply Mode (260-500kVA)
MANUAL BYPASS
RESERVE INPUT
OUTPUT
STATIC SWITCH
RECTIFIER INPUT
LOAD
BATTERY BANK
SWITCH
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flow
Power Flow
Power Flow
MANUAL BYPASS
RESERVE INPUT
RECTIFIER INPUT
BATTERY BANK
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flow
Power Flow
UPS1
UPS2
Power Flow
OUTPUT
STATIC SWITCH SWITCH
Power Flow
Power Flow
Power Flow
When the inverter is in abnormal situations such as over temperature, long-time
overload, output short circuit, abnormal output voltage and exhausted battery, the
inverter will shut down itself for self-protection. If the reserve AC power is normal,
the static switch of each parallel UPS will switch to the reserve AC power to supply
power to the loads without any interruption of power supply. After the abnormal
situations mentioned above are eliminated, the static switch will switch back to the
main AC source (see Figure 3-8-a and 3-8-b).

13
Ultron NT Series
3.9 Maintenance Bypass Mode (Parallel)
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
Power Flow
BATTERY BANK
Power Flow
STATIC SWITCHINVERTERRECTIFIER
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
BATTERY BANK
Power Flow
STATIC SWITCHINVERTERRECTIFIER
Power Flow
LOAD
UPS 1
UPS 2
Power Flow
Power Flow
Power Flow
Figure 3-9-a: Parallel Status Block of Maintenance Bypass Mode (10-200kVA)
MANUAL BYPASS
RESERVE INPUT
OUTPUT
STATIC SWITCH
RECTIFIER INPUT
LOAD
BATTERY BANK
SWITCH
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flow
Power Flow
MANUAL BYPASS
RESERVE INPUT
RECTIFIER INPUT
BATTERY BANK
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flow
UPS1
UPS2
Power Flow
OUTPUT
STATIC SWITCH SWITCH
Power Flow
Power Flow
Power Flow
Figure 3-9-b: Parallel Status Block of Maintenance Bypass Mode (260-500kVA)

14
Chapter 3 Operation Modes
When maintenance is needed and the reserve AC power is normal, the parallel UPS
units can be switched from inverter mode to bypass mode manually with continuous
power delivering to the loads. Under such conditions, the internal power will be
completely cut off except that each parallel UPS's terminals and manual bypass
breaker or switch still have high voltage. As a result, risks will not exist in the parallel
UPS units so service personnel can perform maintenance safely (see Figure 3-9-a
and 3-9-b).
3.10 Hot Standby Redundancy
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AC power of UPS2 (see Figure 3-10-a and 3-10-b). Such configurations could
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Figure 3-10-a: Status Block of Hot-standby Redundancy (10-200kVA)
RECTIFIER INPUT
RESERVE
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
Power Flow
BATTERY BANK
Power Flow
STATIC SWITCHINVERTERRECTIFIER
RECTIFIER INPUT
MAINS BREAKER
RESERVE INPUT
BREAKER
MANUAL BYPASS
BREAKER
OUTPUT
BREAKER
Power Flow
BATTERY BANK
Power Flow
STATIC SWITCHINVERTERRECTIFIER
LOAD
UPS 1
UPS 2
Power Flow
Power Flow
Power Flow
Power Flow
UPS 1 OUTPUT
UPS 2 OUTPUT
RESERVE INPUT

15
Ultron NT Series
MANUAL BYPASS
RESERVE INPUT
OUTPUT
STATIC SWITCH
RECTIFIER INPUT
LOAD
BATTERY BANK
SWITCH
SWITCH
SWITCH
RESERVE
MAINS SWITCH RECTIFIER INVERTER
Power Flow
Power Flow
Power Flow
Power Flow
MANUAL BYPASS
RESERVE INPUT
RECTIFIER INPUT
BATTERY BANK
SWITCH
SWITCH
MAINS SWITCH RECTIFIER INVERTER
Power Flow
Power Flow
UPS1
UPS2
OUTPUT
STATIC SWITCH SWITCH
Power Flow
Power Flow
UPS1 OUTPUT
UPS2 OUTPUT
RESERVE INPUT
Figure 3-10-b: Status Block of Hot-standby Redundancy (260-500kVA)
In normal condition, the UPS2 supplies the loads. If the UPS2 fails, the static switch
will switch to UPS1 (the reserve AC power of UPS2) without a break of the power
supply. In order to reduce costs, the O/P of UPS1 could simultaneously connect to
UPS2, UPS3, etc..
3.11 Common Battery
To save on costs and installation space, the parallel UPS units can share the same
external battery cabinet(s). Please see Figure 3-11-a and 3-11-b.