Mounting Instructions
See Figures 1 & 2, pages 17 & 18
1. The enclosure is designed for vertical surface
mounting in a dry location. It should not be used
where a water-tight or weatherproof enclosure
is required.
Never mount the enclosure
immediately beside or above
heat-generating equipment, or directly below
water and steam pipes.
Comply with the following mounting
requirements:
a. Mount the enclosure in a vertical
position, allowing four (4) inches
minimum clearance on all sides, for
maximum cooling efficiency.
b. Fasten the enclosure securely on a level
surface with the mounting tabs provided.
See Figure 1 for enclosure dimensions.
c. Shock and excessive vibration are
detrimental to controller performance and
life. Vibration can cause general
deterioration of connections, and
component damage. Therefore, shock-
mount the controller if it is subjected to
external vibrations.
2. If the motor is to be foot mounted, bolt the
motor to a firm, flat foundation. If the
foundation is not flat, use shims to prevent
strain when tightening the bolts. If the motor
is to be connected directly to a machine, be
sure of correct alignment. Pulleys and
couplings must slip freely onto the motor
shaft.
Never hammer the pulleys,
couplings, or motor shaft, nor
overtighten drive belts or timing chains. Bearing
damage could result.
Wiring Instructions
Refer to the data label inside the enclosure
cover and be sure the input voltage and
frequency to the controller complies with its
rating. A surge suppressor (varistor) protects
the controller from normal line transients and
surges. However, to prevent problems from
high-energy transients and large surges,
observe the following:
1. Place the controller on a feeder line separate
from that supplying large inductive loads.
2. If the input power to the controller comes
directly from a transformer, always switch
power ON and OFF between the transformer
secondary and the controller.
Never make or break power
in the transformer primary.
Transients could be generated which could
damage the controller.
3. If the controller must be fed from an AC
circuit which also supplies highly inductive
loads, additional suppression may be
required to limit transients or surges to 150%
of peak line voltage.
Never use power factor
correction capacitors on the
input line to the controller. These capacitors can
damage the solid-state components.
The wire size of the input power and motor
wiring can be determined from Table 1 and the
controller data label.
1. Do not use wire larger than
#12 AWG. Oversize or solid
wire, as well as oversize screwdrivers for
electrical connections, can break terminal board
barriers.
2. All wiring must comply with the national and
local electrical codes.
Use the 3/4-14 NPT tapped conduit holes in the
enclosure to facilitate wiring.
All external wiring for low voltage signal
sources, e.g., potentiometers, tachometer
generators, transducers, should be run in
separate conduit from all other wiring. Use
twisted wire (5 to 6 twists per foot) or shielded
cable. Maintain the separation of power and
signal wiring within the enclosure.
Pickup from unwanted
signals can cause erratic
operation and/or controller damage.
6
P-3026 • Doc. No. 60881 • Boston Gear
®
Ratiotrol
®
DC Motor Speed Control
Installation
Section II
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION
