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nfpa-70_440_hvac-equipment.md
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@@ -6,7 +6,7 @@ tags:
- authorship/other
- destiny/uncertain
- exclude-from-word-count
- status/incomplete
- status/draft
- topic/construction/electrical
- type/media
title: Article 440 Air-Conditioning and Refrigerating Equipment
@@ -25,27 +25,41 @@ The definitions in this section shall apply only within this article.
##### Branch-Circuit Selection Current.
The value in amperes to be used instead of the rated-load current in determining the ratings of motor branch-circuit conductors, disconnecting means, controllers, and branch-circuit short-circuit and ground-fault protective devices wherever the running overload protective device permits a sustained current greater than the specified percentage of the rated-load current. The value of branch-circuit selection current will always be equal to or greater than the marked rated-load current.
The value in amperes to be used instead of the rated-load current
in determining the ratings of motor branch-circuit conductors,
disconnecting means, controllers,
and branch-circuit short-circuit and ground-fault protective devices
wherever the running overload protective device permits a sustained current
greater than the specified percentage of the rated-load current.
The value of branch-circuit selection current
will always be equal to or greater than the marked rated-load current.
##### Leakage-Current Detector-Interrupter (LCDI).
A device provided in a power supply cord or cord set that senses leakage current flowing between or from the cord conductors and interrupts the circuit at a predetermined level of leakage current.
A device provided in a power supply cord or cord set
that senses leakage current flowing between or from the cord conductors
and interrupts the circuit at a predetermined level of leakage current.
##### Rated-Load Current.
The current of a hermetic refrigerant motor-compressor resulting when it is operated at the rated load, rated voltage, and rated frequency of the equipment it serves.
The current of a hermetic refrigerant motor-compressor
resulting when it is operated at the rated load,
rated voltage, and rated frequency
of the equipment it serves.
### 440.3 Other Articles.
#### 440.3(A) Article 430.
These provisions are in addition to, or amendatory of,
the provisions of Article 430 and other articles in this Code,
the provisions of [[nfpa-70_430_motors|Article 430]]
and other articles in this Code,
which apply except as modified in this article.
#### 440.3(B) Articles 422, 424, or 430.
The rules of Articles 422, 424, or 430, as applicable,
The rules of Articles [[nfpa-70_422_appliances|422]],
[[nfpa-70_424|424]], or [[nfpa-70_430_motors|430]], as applicable,
shall apply to air-conditioning and refrigerating equipment
that does not incorporate a hermetic refrigerant motor-compressor.
This equipment includes devices
@@ -60,7 +74,7 @@ Equipment such as room air conditioners,
household refrigerators and freezers,
drinking water coolers, and beverage dispensers
shall be considered appliances,
and Article 422 shall also apply.
and [[nfpa-70_422_appliances|Article 422]] shall also apply.
#### 440.3(D) Other Applicable Articles.
@@ -82,9 +96,18 @@ shall also comply with the applicable provisions of Table 440.3(D).
#### 440.4(A) Hermetic Refrigerant Motor-Compressor Nameplate.
A hermetic refrigerant motor-compressor shall be provided with a nameplate that shall indicate the manufacturer's name, trademark, or symbol; identifying designation; phase; voltage; and frequency.
The rated-load current in amperes of the motor-compressor shall be marked by the equipment manufacturer on either or both the motor-compressor nameplate and the nameplate of the equipment in which the motor-compressor is used.
The locked-rotor current of each single-phase motor-compressor having a rated-load current of more than 9 amperes at 115 volts, or more than 4.5 amperes at 230 volts, and each polyphase motor-compressor shall be marked on the motor-compressor nameplate.
A hermetic refrigerant motor-compressor shall be provided with a nameplate
that shall indicate the manufacturer's name, trademark, or symbol;
identifying designation; phase; voltage; and frequency.
The rated-load current in amperes of the motor-compressor
shall be marked by the equipment manufacturer
on either or both the motor-compressor nameplate
and the nameplate of the equipment in which the motor-compressor is used.
The locked-rotor current
of each single-phase motor-compressor having a rated-load current
of more than 9 amperes at 115 volts, or more than 4.5 amperes at 230 volts,
and each polyphase motor-compressor
shall be marked on the motor-compressor nameplate.
Where a thermal protector complying with 440.52(A)(2) and (B)(2) is used,
the motor-compressor nameplate or the equipment nameplate
shall be marked with the words "thermally protected."
@@ -92,7 +115,7 @@ Where a protective system complying with 440.52(A)(4) and (B)(4)
is used and is furnished with the equipment,
the equipment nameplate shall be marked with the words,
"thermally protected system."
Where a protective system complying with 440.52(A) (4) and (B)(4) is specified,
Where a protective system complying with 440.52(A)(4) and (B)(4) is specified,
the equipment nameplate shall be appropriately marked.
#### 440.4(B) Multimotor and Combination-Load Equipment.
@@ -103,15 +126,21 @@ Multimotor and combination-load equipment shall be provided with a visible namep
> Multimotor and combination-load equipment that is suitable under the provisions of this article for connection to a single 15- or 20-ampere, 120-volt, or a 15-ampere, 208- or 240-volt, single-phase branch circuit shall be permitted to be marked as a single load.
> [!important] Exception No. 2:
> The minimum supply circuit conductor ampacity and the maximum rating of the branch-circuit short-circuit and groundfault protective device shall not be required to be marked on a room air conditioner complying with 440.62(A).
> The minimum supply circuit conductor ampacity and the maximum rating of the branch-circuit short-circuit and ground-fault protective device shall not be required to be marked on a room air conditioner complying with 440.62(A).
> [!important] Exception No. 3:
> Multimotor and combination-load equipment used in one- and two-family dwellings or cord-and-attachment-plugconnected equipment shall not be required to be marked with a short-circuit current rating.
> Multimotor and combination-load equipment used in one- and two-family dwellings or cord-and-attachment-plug-connected equipment shall not be required to be marked with a short-circuit current rating.
#### 440.4(C) Branch-Circuit Selection Current.
A hermetic refrigerant motor-compressor, or equipment containing such a compressor, having a protection system that is approved for use with the motor-compressor that it protects and that permits continuous current in excess of the specified percentage of nameplate rated-load current given in 440.52(B)(2) or (B)(4) shall also be marked with a branch-circuit selection current that complies with
440.52(B)(2) or (B)(4). This marking shall be provided by the equipment manufacturer and shall be on the nameplate(s) where the rated-load current(s) appears.
A hermetic refrigerant motor-compressor, or equipment containing such a compressor,
having a protection system that is approved for use with the motor-compressor that it protects
and that permits continuous current in excess of the specified percentage
of nameplate rated-load current given in 440.52(B)(2) or (B)(4)
shall also be marked with a branch-circuit selection current
that complies with 440.52(B)(2) or (B)(4).
This marking shall be provided by the equipment manufacturer
and shall be on the nameplate(s) where the rated-load current(s) appears.
### 440.5 Marking on Controllers.
@@ -119,12 +148,22 @@ A controller shall be marked with the manufacturer's name, trademark, or symbol;
### 440.6 Ampacity and Rating.
The size of conductors for equipment covered by this article shall be selected from Table 310.16 through Table 310.19 or calculated in accordance with 310.14 as applicable. The required ampacity of conductors and rating of equipment shall be determined according to
440.6(A) and 440.6(B).
The size of conductors for equipment covered by this article
shall be selected from Table 310.16 through Table 310.19
or calculated in accordance with 310.14 as applicable.
The required ampacity of conductors and rating of equipment
shall be determined according to 440.6(A) and 440.6(B).
#### 440.6(A) Hermetic Refrigerant Motor-Compressor.
For a hermetic refrigerant motor-compressor, the rated-load current marked on the nameplate of the equipment in which the motorcompressor is employed shall be used in determining the rating or ampacity of the disconnecting means, the branch-circuit conductors, the controller, the branch-circuit short-circuit and ground-fault protection, and the separate motor overload protection. Where no ratedload current is shown on the equipment nameplate, the rated-load current shown on the compressor nameplate shall be used.
For a hermetic refrigerant motor-compressor,
the rated-load current marked on the nameplate of the equipment in which the motor compressor is employed
shall be used in determining the rating or ampacity of the disconnecting means,
the branch-circuit conductors, the controller,
the branch-circuit short-circuit and ground-fault protection,
and the separate motor overload protection.
Where no rated load current is shown on the equipment nameplate,
the rated-load current shown on the compressor nameplate shall be used.
> [!important] Exception No. 1:
> Where so marked, the branch-circuit selection current shall be used instead of the rated-load current to determine the rating or ampacity of the disconnecting means, the branch-circuit conductors, the controller, and the branch-circuit short-circuit and ground-fault protection.
@@ -134,18 +173,32 @@ For a hermetic refrigerant motor-compressor, the rated-load current marked on th
#### 440.6(B) Multimotor Equipment.
For multimotor equipment employing a shaded-pole or permanent split-capacitor-type fan or blower motor, the full-load current for such motor marked on the nameplate of the equipment in which the fan or blower motor is employed shall be used instead of the horsepower rating to determine the ampacity or rating of the disconnecting means, the branch-circuit conductors, the controller, the branch-circuit short-circuit and ground-fault protection, and the separate overload protection. This marking on the equipment nameplate shall not be less than the current marked on the fan or blower motor nameplate.
For multimotor equipment employing a shaded-pole
or permanent split-capacitor-type fan or blower motor,
the full-load current for such motor
marked on the nameplate of the equipment in which the fan or blower motor is employed
shall be used instead of the horsepower rating
to determine the ampacity or rating of the disconnecting means,
the branch-circuit conductors, the controller,
the branch-circuit short-circuit and ground-fault protection,
and the separate overload protection.
This marking on the equipment nameplate
shall not be less than the current marked on the fan or blower motor nameplate.
### 440.7 Highest Rated (Largest) Motor.
In determining compliance with this article and with 430.24, 430.53(B) and 430.53(C), and 430.62(A), the highest rated (largest) motor shall be considered to be the motor that has the highest rated-load current. Where two or more motors have the same highest ratedload current, only one of them shall be considered as the highest rated (largest) motor. For other than hermetic refrigerant motorcompressors, and fan or blower motors as covered in 440.6(B), the full-load current used to determine the highest rated motor shall be the equivalent value corresponding to the motor horsepower rating selected from Table 430.248, Table 430.249, or Table 430.250.
In determining compliance with this article and with 430.24, 430.53(B) and 430.53(C), and 430.62(A), the highest rated (largest) motor shall be considered to be the motor that has the highest rated-load current. Where two or more motors have the same highest rated load-current, only one of them shall be considered as the highest rated (largest) motor. For other than hermetic refrigerant motor-compressors, and fan or blower motors as covered in 440.6(B), the full-load current used to determine the highest rated motor shall be the equivalent value corresponding to the motor horsepower rating selected from Table 430.248, Table 430.249, or Table 430.250.
> [!important] Exception:
> Where so marked, the branch-circuit selection current shall be used instead of the rated-load current in determining the highest rated (largest) motor-compressor.
### 440.8 Single Machine.
An air-conditioning or refrigerating system shall be considered to be a single machine under the provisions of 430.87, Exception No. 1, and 430.112, Exception. The motors shall be permitted to be located remotely from each other.
An air-conditioning or refrigerating system
shall be considered to be a single machine
under the provisions of [[nfpa-70_430_motors#^87-ex1|430.87, Exception No. 1]],
and [[nfpa-70_430_motors#^112-ex|430.112, Exception]].
The motors shall be permitted to be located remotely from each other.
### 440.9 Grounding and Bonding.
@@ -155,7 +208,7 @@ Where equipment is installed outdoors on a roof, an equipment grounding conducto
#### 440.10(A) Installation.
Motor controllers or industrial control panels of multimotor and combination-load equipment shall not be installed where the available fault current exceeds its short-circuit current rating as marked in accordance with 440.4(B).
Motor controllers or industrial control panels of multimotor and combination-load equipment shall not be installed where the available fault current exceeds its short-circuit current rating as marked in accordance with [[#440.4(B) Multimotor and Combination-Load Equipment.|440.4(B)]].
#### 440.10(B) Documentation.
@@ -175,28 +228,42 @@ A disconnecting means serving a hermetic refrigerant motor-compressor shall be s
##### 440.12(A)(1) Ampere Rating.
The ampere rating shall be at least 115 percent of the nameplate rated-load current or branch-circuit selection current, whichever is greater.
The ampere rating shall be at least 115 percent of
the nameplate rated-load current
or branch-circuit selection current,
whichever is greater.
> [!important] Exception:
> A listed unfused motor circuit switch, without fuseholders, having a horsepower rating not less than the equivalent horsepower determined in accordance with 440.12(A)(2) shall be permitted to have an ampere rating less than 115 percent of the specified current.
##### 440.12(A)(2) Equivalent Horsepower.
To determine the equivalent horsepower in complying with the requirements of 430.109, the horsepower rating shall be selected from
Table 430.248, Table 430.249, or Table 430.250 corresponding to the rated-load current or branch-circuit selection current, whichever is greater, and also the horsepower rating from Table 430.251(A) or Table 430.251(B) corresponding to the locked-rotor current. In case the nameplate rated-load current or branch-circuit selection current and locked-rotor current do not correspond to the currents shown in
Table 430.248, Table 430.249, Table 430.250, Table 430.251(A), or Table 430.251(B), the horsepower rating corresponding to the next higher value shall be selected. In case different horsepower ratings are obtained when applying these tables, a horsepower rating at least equal to the larger of the values obtained shall be selected.
To determine the equivalent horsepower
in complying with the requirements of [[nfpa-70_430_motors#430.109 Type.|430.109]],
the horsepower rating shall be selected from
[[nfpa-70_430_motors#^t248|Table 430.248]],
[[nfpa-70_430_motors#^t249|Table 430.249]],
or [[nfpa-70_430_motors#^t250|Table 430.250]]
corresponding to the rated-load current or branch-circuit selection current, whichever is greater,
and also the horsepower rating from [[nfpa-70_430_motors#^t251a|Table 430.251(A)]]
or [[nfpa-70_430_motors#^t251b|Table 430.251(B)]]
corresponding to the locked-rotor current.
In case the nameplate rated-load current or branch-circuit selection current and locked-rotor current
do not correspond to the currents shown in Table 430.248, Table 430.249,
Table 430.250, Table 430.251(A), or Table 430.251(B),
the horsepower rating corresponding to the next higher value shall be selected.
In case different horsepower ratings are obtained when applying these tables,
a horsepower rating at least equal to the larger of the values obtained shall be selected.
#### 440.12(B) Combination Loads.
Where the combined load of two or more hermetic refrigerant motor-compressors or one or more hermetic refrigerant motorcompressor with other motors or loads may be simultaneous on a single disconnecting means, the rating for the disconnecting means shall be determined in accordance with 440.12(B)(1) and (B)(2).
Where the combined load of two or more hermetic refrigerant motor-compressors or one or more hermetic refrigerant motor-compressor with other motors or loads may be simultaneous on a single disconnecting means, the rating for the disconnecting means shall be determined in accordance with 440.12(B)(1) and (B)(2).
##### 440.12(B)(1) Horsepower Rating.
The horsepower rating of the disconnecting means shall be determined from the sum of all currents, including resistance loads, at the rated-load condition and also at the locked-rotor condition. The combined rated-load current and the combined locked-rotor current so obtained shall be considered as a single motor for the purpose of this requirement as required by 440.12(B)(1)(a) and (B) (1) (b).
The horsepower rating of the disconnecting means shall be determined from the sum of all currents, including resistance loads, at the rated-load condition and also at the locked-rotor condition. The combined rated-load current and the combined locked-rotor current so obtained shall be considered as a single motor for the purpose of this requirement as required by 440.12(B)(1)(a) and (B)(1)(b).
* (a) The full-load current equivalent to the horsepower rating of each motor, other than a hermetic refrigerant motor-compressor, and fan or blower motors as covered in 440.6(B) shall be selected from Table 430.248, Table 430.249, or Table 430.250. These fullload currents shall be added to the motor-compressor rated-load current(s) or branch-circuit selection current(s), whichever is greater, and to the rating in amperes of other loads to obtain an equivalent full-load current for the combined load.
* (a) The full-load current equivalent to the horsepower rating of each motor, other than a hermetic refrigerant motor-compressor, and fan or blower motors as covered in 440.6(B) shall be selected from Table 430.248, Table 430.249, or Table 430.250. These full-load currents shall be added to the motor-compressor rated-load current(s) or branch-circuit selection current(s), whichever is greater, and to the rating in amperes of other loads to obtain an equivalent full-load current for the combined load.
* (b) The locked-rotor current equivalent to the horsepower rating of each motor, other than a hermetic refrigerant motor-compressor, shall be selected from Table 430.251(A) or Table 430.251(B), and, for fan and blower motors of the shaded-pole or permanent split-capacitor type marked with the locked-rotor current, the marked value shall be used. The locked-rotor currents shall be added to the motor-compressor locked-rotor current(s) and to the rating in amperes of other loads to obtain an equivalent locked-rotor current for the combined load. Where two or more motors or other loads such as resistance heaters, or both, cannot be started simultaneously, appropriate combinations of locked-rotor and rated-load current or branch-circuit selection current, whichever is greater, shall be an acceptable means of determining the equivalent locked-rotor current for the simultaneous combined load.
@@ -205,15 +272,15 @@ The horsepower rating of the disconnecting means shall be determined from the su
##### 440.12(B)(2) Full-Load Current Equivalent.
The ampere rating of the disconnecting means shall be at least 115 percent of the sum of all currents at the rated-load condition determined in accordance with 440.12(B)(1).
The ampere rating of the disconnecting means shall be at least 115 percent
of the sum of all currents at the rated-load condition determined in accordance with 440.12(B)(1).
> [!important] Exception:
> A listed unfused motor circuit switch, without fuseholders, having a horsepower rating not less than the equivalent horsepower determined by 440.12(B)(1) shall be permitted to have an ampere rating less than 115 percent of the sum of all currents.
#### 440.12(C) Small Motor-Compressors.
For small motor-compressors not having the locked-rotor current marked on the nameplate, or for small motors not covered by Table
430.247, Table 430.248, Table 430.249, or Table 430.250, the locked-rotor current shall be assumed to be six times the rated-load current.
For small motor-compressors not having the locked-rotor current marked on the nameplate, or for small motors not covered by Table 430.247, Table 430.248, Table 430.249, or Table 430.250, the locked-rotor current shall be assumed to be six times the rated-load current.
#### 440.12(D) Disconnecting Means.