Cut Sheet

TYPE 3R WEATHERFLO TypE 3R VEnTEd EncLOsuREs
Spec-00161 I
PH 763.422.2211 • • FAX [phone] • • PENTAIRPROTECT.COMEQUIPMENT PROTECTION CONTRACTOR 4
CRITICAL PARAMETERS (UPPER TEMPERATURE LIMITS)
Enclosure Heat Load Calculations
Drive heat:
W
D
= [(HP x 745.7 Watts/HP) / E
M
] x (1-E
D
) [Watts]
Total heat:
Estimate an additional 25%
a
for wire connections and other
components.
W
T
= W
D
x 1.25
a
[Watts]
Required airflow:
CFM = (W
T
x 3.16) / (T
int
- T
amb
) [ft.
3
/ min.]
a
This is an estimated factor. Further investigation is necessary to
obtain actual total heat dissipated in enclosure.
Variables
Variable Descriptions
Variables
Typical Values
Maximum ambient temperature
T
amb
104 F
Maximum internal temperature
T
int
122 F
Typical temperature rise
(T
int
- T
amb
)
15 F
Full-load drive power HP —
Motor efficiency
b
E
M
.80-.96
Drive efficiency
b
E
D
.96-.98
Drive heat loss
W
D
—
Total heat loss
W
T
—
Required airflow CFM —
b
Use full-load efficiency. Motor and drive efficiency will vary based on HP and voltage.
Sample Values
Drive
HorsePower
(hp)
Typical Full Load
Rating - Motor Efficiency
Typical Full Load
Rating - Drive Efficiency
Drive Heat
Loss W
D
(W)
Additional Heat
Loss
a
(W)
Total Heat
Loss W
T
(W)
Airflow when
t
int
- T
amb
= 15 F
(CFM)
3 .86 .97 78 20 98 21
10 .90 .97 249 62 311 65
25 .91 .97 615 154 768 162
40 .92 .98 648 162 811 171
75 .93 .98 1203 301 1503 317
100 .94 .98 1587 397 1983 418
a
Additional Heat Loss - This is an estimated factor. Further investigation is necessary to obtain actual total heat dissipated in enclosure.
CRITICAL PARAMETERS (LOWER TEMPERATURE
LIMITS)
Determine the ambient operating temperature range of the drive. A
typical operating range is from 14 to 122 F (-10 to 50 C). For outdoor
assemblies in northern climates, the lower operating temperature
may be below the lower temperature limit. To ensure that cold
starts are not below the low limit temperature, the addition of a
heater is recommended.
Hoffman has 100-, 200-, 400-, and 800-W heaters available with
adjustable thermostats from 0-100 F. For additional information,
see the Thermal Management chapter.
WEATHERFLO
Catalog Number
Recommended Heater (115 VAC) Recommended Heater (230 VAC) Heater Size (W)
Estimated Temperature
Rise Above Ambient (ºF)
WF3LP DAH2001A DAH2002A 200 55
WF10LP DAH2001A DAH2002A 200 46
WF25LP DAH2001A DAH2002A 200 40
WF40LP DAH2001A DAH2002A 200 33
WF75LP DAH4001B DAH4002B 400 41
WF100LP DAH4001B DAH4002B 400 37