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RH25C, RH50C 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
RH25, 50C or non-inductive RH25, 50 C N windings.  The cement molding construction conforms 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

Resistance Range

Temperature coefficient [ppm/C] (-55C,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

+-100

+-50

+-30

RH25 C

Wire Wound

20W

8W

.022Ω-25KΩ

0.1Ω- 10KΩ

+-200

0.022Ω-0.09Ω

0.1Ω- 0.976Ω

1Ω- 19.6Ω

20Ω-

+-0.1(B) +-0.25(C) +-0.5(D) +-1(F) +-2(G) +-5(J)

1Ω- 0.4Ω- 0.2Ω- 0.1Ω- 0.05Ω- 0.02Ω-

RH50 C

Wire wound

30, 50W*

10W

.048Ω- 50KΩ

0.2Ω- 20KΩ

/

0.048Ω-0.09Ω

0.1Ω- 0.976Ω

1Ω- 19.6Ω

20Ω-

FRH25 C

Thick Film

15W

5W

/

2Ω- 2MΩ

2Ω- 2MΩ

/

/

/

/

FRH50 C

Thick Film

25W

8W

/

2Ω- 2MΩ

2Ω- 2MΩ

/

/

/

/

*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

Temperature Range	-55C to 250C
Insulation Resistance	20MΩ minimum  (at more than 100Ω)
Dielectric Strength	+-[0.2%+0.05Ω] AC2000V for 1 min, Max leakage current : 2mA
Short Time Overload	+-[0.5%+0.05Ω] Rated power X 5 for 5 secs
Thermal Shock	+-[0.5%+0.05Ω] Power rating 30 min, -55C 15 to 30 min
Moisture Resistance	+-[0.5%+0.05 Ω] 40C, 95% RH, DC100V case to terminal (500hrs.)
Load Life	+-[1%+0.05 Ω] Power rating 90 min on, 30 min off, 1000 hours

SURFACE TEMPERATURE INCREASE VERSUS POWER LOAD

DIMENSIONS

Model	Dimensions(mm)			Weight [g]
	L1	L2	L3
RH 25 C	49.4	27.1	18.3	29
RHC 50 C	70.8	49.3	39.7	16
FRH 25 C	49.4	27.1	18.3	29
FRH 50 C	70.8	49.3	39.7	16.5

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