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RH,FRH METAL CLAD,
WIRE WOUND
, CEMENT ENCASED
RESISTORS

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RH25C and  RH50C are aluminum housed, metal clad, cement encased resistors.  These models come in standard,
RH windings or non-inductive, RHN windings.  The cement molding construction conforms 100% to RoHS guidelines.
Construction is completely welded. These models also
mount on chassis to utilize heat sink cooling.  RH25/50C
exhibit high stability at conventional power.

GENERAL SPECIFICATIONS

Model Element
Type
Rated Power
[W]
Resistance
Range [
目]
Temperature coefficient [ppm/C]
(-55
C,25C,250C)
Resist-
ance
Tol.
Min
Ohmic
Value
With
Heat
Sink
In
Free
Air
Induc-
tive
Non-
Induc-
tive
-15C,
25C,
105C
Measuring Temp. -55, 25C, 250C
+200 +200 +-100 +-50 +-30
RH25C Wire
Wound
20 8 .027-25K 0.27-
10K
/ 0.039目-0.09目 0.1目-
0.976目
1目-
19.6目
20目- +-0.1(B)
+-0.25(C)
+-0.5(D)
+-1(F)
+-2(G)
+-5(J)
1目-
0.4目-
0.2目-
0.1目-
0.05目-
RH50C Wire
wound
*30,
*50
10 .068-
50K
0.1-
20K
/ / 0.1目-
0.976目
1目-
19.6目
20目-
FRH25C Thick
Film
15 5 / 2-
2M
2目-
2M目
/ / / /
FRH50C Thick
Film
25 8 / 2-
2M
2目-
2M目
/ / / /

*30W on heat sink size : AL 178 X 127 X 51 X 1t,  50W on heat sink size : AL 305 X 305X X 2t

CHARACTERISTICS                                                                                                          Values in [ ] mean change in W after test

RH FRH TEST
Temperature Range -55C to 250C
Insulation Resistance 20M戒 minimum
Dielectric Strength ▽[0.2%+0.05目] ▽[0.5%+0.05目] AC1500V for 1 min, Max leakage current: 2mA
Short Time Overload ▽[0.5%+0.05目] ▽[1%+0.05目] Rated power X5 for 5sec.
Thermal Shock [0.5%+0.05] [1%+0.05] Power rating 30 min, -55C 15-30 min.
Load Life

30W : ▽[1%+0.05 ]
50W : ▽[3%+0.05 ]

[2%+0.05] Power rating 90 min on, 30 min off, 500 hours

SURFACE TEMPERATURE INCREASE VERSUS POWER LOAD

DIMENSIONS

Model

Dimensions(mm)

Weight
[g]

L1

L2

L3

RH25C

49.4

27.1

18.3

16.5
RHC50C

70.8

49.3

39.7

35
FRH25C 49.4 27.1 18.3 16.5
FRH50C 70.8 49.3 39.7 35

FREQUENCY CHARACTERISTIC CURVES

DERATING CURVE

RHC resistor have an operating temperature rage of -55C to 250C
Derating is required for reduced chassis mounting area and for high ambient temperatures.
The following curves apply to operation of unmounted resistors.
Heat sink size [mm]:
178 X 127 X 51 X 1t (RH 25 C)
305 X 305 X 2 (RH 50 C)

ORDERING PROCEDURE EXAMPLE

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