Electrical Code Information
Compliance with Local, State, and National Codes is a must on every HVAC Installation. This page
discusses the criteria regarding minimum working spaces as defined in the 2005 National Electric
Code. The main concern is the safety of the HVAC service / maintenance person. Minimum working
clearances are specified in the National Electric Code (NEC) Article 110.26
For electrical equipment that from ground to power the voltage is 600 volts or less:
The National Electric Code specifically states that service area around electrical equipment shall provide
sufficient access, and shall be properly maintained in order to permit safe operation and maintenance of the
equipment. Table 110.26 as well as the figures beside the table describe the minimum clearance for proper
service and access to electrical equipment.
Trane residential and light commercial condensing units ranging from 1 to 6 ton require access to the side
service panel as indicated on the previous pages to gain access to the electrical controls.
Minimum Clear Distance
Condition 1
Condition 2
Condition 3
Nominal
Voltage to
Ground
0-150
900 mm (3 FT)
900 mm (3 FT)
900 mm (3FT)
151-600
900 mm (3FT)
1 M (3.5FT)
1.2 mm (4FT)
Note: Where the conditions are as follows
Condition 1 -
Exposed live parts on one side and no live or grounded parts
on the other side of the working space, or exposed live parts on both sides
effectively guarded by suitable wood or other insulating materials. Insulated
wire or insulated busbars operating at not over 300 volts to ground shall not
be considered live parts
Condition 2 -
Exposed live parts on one side and grounded parts on the
other side. Concrete, brick, or tile walls shall be considered as grounded.
Condition 3 -
Exposed live parts on both sides of the work space (not
guarded as provided in Condition 1) with the operator between.
Table 110.26(A)(1) Working Clearances
Pg. 15
Reprinted with permission from NFPA 70-2005, National Electrical Code®, Copyright © 2004, National Fire
Protection Association. This reprinted material is not the complete and official position of the NFPA on the
referenced subject, which is represented only by the standard of it’s entirety.
National Electrical Code and NEC are registered trademarks of the National Fire Protection Association, Quincy, MA.
The table and figure below are excerpts from the National Electric Code 2002:
Condition 1
(3 ft min. for 151 - 600 V)
Condition 2
(Space would increase to 3 1/2 ft for 151 - 600 V)
Condition 3
(Space would increase to 4 ft for 151 - 600 V)
