Help for Webmasters « back to results for ""
Below is a cache of http://www.batterypoweronline.com/images/PDFs_articles_whitepaper_appros/APCSafetyCodes.pdf. It's a snapshot of the page taken as our search engine crawled the Web.
The web site itself may have changed. You can check the current page or check for previous versions at the Internet Archive. Yahoo! is not affiliated with the authors of this page or responsible for its content.
Battery Technology for Data Centers and Network Rooms: Safety Codes






Battery Technology for
Data Centers and
Network Rooms:
Safety Codes
White Paper # 31
Revision 5
2003 American Power Conversion. All rights reserved. No part of this publication may be used, reproduced, photocopied, transmitted, or
stored in any retrieval system of any nature, without the written permission of the copyright owner. www.apc.com Rev 2003-1
2



Executive Summary
Fire safety regulations and their application to UPS battery installations are reviewed. In
some cases, fire codes do not clearly recognize improvements in battery safety resulting
from changing battery technology. Valve Regulated Lead Acid (VRLA) batteries are
frequently deployed within data centers and network rooms without the need for the
elaborate safety systems that are required for Vented (Flooded) Lead Acid batteries. Proper
interpretation of the fire codes is essential in the design and implementation of data centers
and network rooms.



2003 American Power Conversion. All rights reserved. No part of this publication may be used, reproduced, photocopied, transmitted, or
stored in any retrieval system of any nature, without the written permission of the copyright owner. www.apc.com Rev 2003-1
3
Introduction

There are a wide number of standards and codes that apply to battery systems and battery rooms. At the
local level, the ones that matter most are the Fire Codes. Initially, fire codes for stationary lead acid
batteries were written for large systems utilizing vented (also called flooded or wet cell) lead acid
batteries that supported data centers and network rooms. These systems are typically located in rooms
separate from the equipment they support. These batteries continuously vent hydrogen gas and contain
electrolyte in liquid form. Consequently, special ventilation and spill containment systems must be
employed.

Smaller and distributed back-up power systems are typically located much closer to the equipment they
protect. They generally use Valve Regulated Lead Acid (VRLA) batteries. VRLA batteries are designed to
recombine hydrogen and oxygen and emit only extremely small amounts of hydrogen under normal
operating conditions. Normal room ventilation is sufficient to remove any hydrogen, so special ventilation is
not required.

The electrolyte in a VRLA battery is not in liquid form but is immobilized. The most common technology,
termed Absorbed Glass Mat (AGM) uses a highly porous, absorbent micro fiberglass mats that immobilize
the electrolyte and prevent it from spilling. A crack or hole in the casing of a VRLA battery using AGM
technology will not result in a measurable electrolyte spill. Spill containment with VRLA batteries is
therefore not meaningful or appropriate.
Code of Federal Regulations

Flooded batteries are required to comply with the Occupational Safety and Health Administration (OSHA)
Regulation 29 CFR 1926.441, Battery Rooms and Battery Charging. This regulation applies to batteries of
the unsealed type installed in new construction. Unsealed in this case means flooded batteries. Under
this regulation ventilation, worker protection, acid flushing and neutralization are required. If using flooded
batteries please see the OSHA web site
www.osha.gov
or specific details on how to comply

VRLA batteries are of the sealed type so OSHA regulation 29 CFR does not apply.

The Environmental Protection Agency (EPA) Emergency Planning and Community Right-to-know Act
(EPCRA) requires owners to inform local authorities when their facilities have large volumes (actually
reported in weight) of hazardous materials such as sulfuric acid (present in lead-acid battery electrolyte).
These laws are spelled out in 42 U.S.C. 9601, also known as Title III of SARA, and 42 U.S.C. 1101.
These requirements will be discussed later in this paper, and are explained in detail in White Paper #32.

2003 American Power Conversion. All rights reserved. No part of this publication may be used, reproduced, photocopied, transmitted, or
stored in any retrieval system of any nature, without the written permission of the copyright owner. www.apc.com Rev 2003-1
4
Fire Codes
The two main codes in the United States relating to battery systems are the Uniform Fire Code (UFC)
1
and
the International Fire Code (IFC)
2
.

Originally published by the Western Fire Chiefs Association, the UFC is now published by the National Fire
Protection Association (NFPA - 1)
3
as of 2003.

The International Code Council (ICC) writes the IFC. The ICC was created in 1994 when the Southern
Building Code Congress International (SBCCI), the International Conference of Building Officials (ICBO),
and the Building Officials and Code Administrators International (BOCA) united to create a set of
harmonized standards.


Model codes are written by organizations and published every few years. A locality, town, county, or state,
can choose which code (and which version of the code) to adopt and enforce. For example, the entire
State of Alaska adopted the IFC, while only certain towns in Arizona have adopted it. Many jurisdictions still
use the 1994 or 1997 UFC. Checking with the local safety inspector is the best method to determine which
one applies to a specific installation. Local authorities can also modify the codes. Under the codes, battery
systems are subject to special installation requirements, depending upon amount of electrolyte and battery
technology.

Codes change with each rewrite and jurisdictions use differing versions of codes. This paper can only
generalize about codes. Checking with a local authority is essential in order to determine what code they
enforce.
Application of the Codes to Different Battery
Technologies
Before applying the codes, one must understand how the codes set criteria for when they are to be
enforced. There are four questions that must be answered:
1. What is a Battery System?
2. How many gallons of electrolyte are in this Battery System?
3. Is the electrolyte free-flowing liquid or is it immobilized?
4. What is electrolyte volume at which the code applies?

What is a Battery System?
Under the UFC definition,
4
a battery system consists of three interconnected subsystems:
A lead-acid battery
A battery charger
2003 American Power Conversion. All rights reserved. No part of this publication may be used, reproduced, photocopied, transmitted, or
stored in any retrieval system of any nature, without the written permission of the copyright owner. www.apc.com Rev 2003-1
5
A collection of rectifiers, inverters, converters and associated electrical equipment as required for
a particular application.


From this definition each individual UPS or DC Plant constitutes one (1) battery system. Smaller,
separately installed UPS are independent and do not have an additive effect on the electrolyte capacity. A
fault in one system will not propagate to the others, as they are independent of each other. The threshold
triggers are defined per battery system and not by facility. The code specifically does not instruct the
summation of independent battery systems.

How many gallons of electrolyte are in a battery system?
Gallons are a liquid measure and the fire codes seek to determine the amount of liquid electrolyte in the
battery system. In a flooded battery system 100% of the electrolyte is in liquid form. The amount of liquid
electrolyte in a VRLA battery solution is very small, about 3% of the electrolyte used in production of the
battery. These values are provided by the battery manufacturer. The liquid electrolyte value in each battery
within the battery system would be added together to arrive at the total for a system.

Is the electrolyte free-flowing liquid or is it immobilized?
The International Fire Code was modified in 2001 to create different rules for VRLA batteries. It recognized
that VRLA batteries have different properties versus flooded batteries. IFC (Section 609) applies to VRLA
battery systems having an electrolyte capacity of more than 50 gallons. The IFC specifically states for
VRLA batteries, The battery systems are permitted to be in the same room with the equipment they
support.
5
The IFC also has requirements for thermal runaway, neutralization, and ventilation.

The 2003 Uniform Fire Code has also changed. Certain requirements, such as spi