INDUSTRI A
RESISTENZE
ELETTRICHE
RFMTX series
ELECTRICAL RATINGS
UL File Number:
NMTR2.E335378 - NMTR8.E335378
DATASHEET
ELECTRICAL RATINGS - Cat. No. RFMTX:
Continuousduty
Cat. No.
Non continuous-duty
Power
Resistance
Max.
Voltage
Tau
Continuousduty Current
Peak.
non-cont
Current
Duty cycle
P
R
Max. V
τ
I maxc
I peak
EDch
[W]
[Ohm]
[V]
[sec]
[A]
[A]
RFMTX 75
65
from 1 to
300
600
300
RFMTX 100
75
from 1.5
to 360
600
300
RFMTX 165
115
from 2 to
720
600
300
= sqrt (P/R)
= V/R
RFMTX 220
150
from 2.2
to 870
600
400
If Ton > τ/10
If Ton < τ/10
Max Power = P
Max Ppeak x EDch = P
EDch =
Pmaxc/Ppeak
= (Imaxc/Ipeak)2
(Max Ppeak = V2/R)
RFMTX 300
195
from 3 to
1100
600
500
RFMTX 400
240
from 3.7
to 1600
600
600
τ = thermal characteristic time of resistor;
EDch = chopper duty cycle, Tonch/Ttotch.
Continuous-duty Current is defined as the value of current in the resistor that
produces the declared value of Power.
Max. Current - Non continuous-duty is the maximum current for each resistor,
calculated as the Voltage applied to the resistor (shall be not more than 600 V)
divided per the value of the Resistance.
I.R.E. INDUSTRIA RESISTENZE ELETTRICHE s.r.l - www.ireresistor.com - e-mail: vendite@ireresistor.com
Via Valtellina, 2 - 20027 Rescaldina (MI) - Tel. (+39) 0331.577.833 - Fax (+39) 0331.577.832 - P. IVA IT11267750153
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