Introduction, Continued), Ramm full wave solid state dc motor speed control – Rapid-Air DUAL SWIVEL REEL WITH DISPLAY KEYPAD: 100 & 1000 SERIES User Manual

Page 10

CaUtion:
1. The voltage feeding P2 and
F– must be isolated from the AC
line. Do not ground P2 or F– to set
up a zero ground reference.
2. Do not bundle signal wires to P2
and F– with AC line motor
connections. If signal wires are
over 18”, use shielded cables.

C. FUSing

The RAMM has provision for a built

in AC line fuse and armature fuse.

The AC line fuse protects the control

against catastrophic failure– if the

fuse blows, the control is miswired,

the motor is shorted or grounded, or

the RAMM control is defective. The

armature fuse provides overload

protection for the motor and control.

Choose the proper size armature fuse

by multiplying the maximum DC motor

amps by 1.7. On domestic 240 Volt

AC lines, separate branch circuit

protection for each line must be

used. All fuses should be normal blow

ceramic 3AG or ABC or equivalent.

1. AC Line Fuse is chosen according
to the maximum rating of the
control:

– 12 AMP fuse for all motors up
to 3/4 HP-90V and 1-1/2 HP-
180VDC.
– 25 AMP fuse for all motors 1
and 1-1/2 HP-90V and 2 and
3 HP-180VDC.
(Use Buss ABC, Littlefuse
326 ceramic fuse or equivalent.)

2. Armature Fuse can be chosen
in accordance with the fuse chart.
note: The armature fuse is
calculated based on the
approximate full load DC current
rating of the motor times a form
factor of 1.5. If motor has
characteristics not consistent
with these approximations, a
different fuse value may have to
be used. Fuses are available from
your distributor.

introduction

(continued)

raMM Full Wave Solid State DC Motor Speed Control

taBLe 4: arMatUre FUSe CHart

2.5

5.0

7.5

10.0

Horsepower

90 VDC

Motor

1/4

1/2

3/4

1-1/2

1/2

1-1/2

12*

25*

* Also used as AC line fuse.

Horsepower

180 VDC

Motor

Approx.

DC Motor Current

(Amps)

Fuse

Rating

(AC Amps)