APPENDIX A
A1.0 INTRODUCTION
Appendix A describes the Drawout Case option for the
MD-3000 Protective Relay. The table below (A-1) lists the
Drawout Case versions.
Table A-1 Ordering Information
Style #
Catalog #
Description
66D2127G01 MD3001
Protective
Relay
– High range PS,
Drawout case
66D2129G01 MD3001-IC MD3001
Protective Relay
- Inner Case
Only
66D2128G01 MD3001-OC MD3001
-
Outer
Case Only
A2.0 GENERAL DESCRIPTION
The purpose of the MD-3001 is to allow the device to be
removed from gear, using a “quick disconnect” type
strategy. The MD-3001 Drawout Relay maintains the same
electrical and operating specifications as the standard MD-
3000 with the addition of the following Drawout connector
specifications.
TABLE A-2 ADDITIONAL SPECIFICATIONS
Relay Make/Break Rating
10A @ 240Vac nominal
0.25A @ 250Vdc break maximum
Terminal Wire Gauge
No. 14 to 10 AWG
Screw Torque Requirements
18 inch-pounds
Meets ANSI C37.90.2 (2004) to 35 V/M
The Drawout Outer Case consists of two assemblies, a
molded plastic outer flange with “quick release” actuators
and locking mechanism, and the aluminum housing with
terminal blocks.
The Drawout terminal block features self-shorting or short-
before-break contacts, for Ct connections that maintain
circuit continuity when the device is removed. These self-
shorting contacts will prevent damaging voltages from
existing across the current transformer windings.
The terminal blocks feature a 2-stage disconnect
operation. Removal of the MD-3001 Inner Chassis will
disconnect the trip circuits and short the Ct secondary
before the unit control power is disconnected. Upon
insertion of the inner chassis, the control power
connections are made before the trip circuits are activated.
This feature provides added security against false
tripping.
A3.0 INSTALLATION
NOTE: Please refer to the following section if you are
using the MD 3001 Drawout Relay.
A3.1 PANEL PREPARATION
When mounting the Drawout Case in a panel, it is
necessary to prepare a cutout for the device. Cutout
Dimensions
. If a standard IQ cutout exists, no additional
panel setup is required; the Drawout will mount in the
existing hole cutouts.
A3.2 MD-3001 DRAWOUT RELAY PARTS LIST
BEFORE MOUNTING THE DRAWOUT RELAY, REVIEW
the table below for ALL OF THE INCLUDED PARTS:
TABLE A-3 MD-3001 DRAWOUT RELAY PARTS LIST
Description
Quantity
MD 3001 Drawout Inner Chassis
1
MD 3001 Drawout Enclosure
1
Outer Flange
1
Mounting Hardware — #10-32 nuts & lock
washers
6 each
MD 3001 Instruction Book — I.B.
02602001E
1
A3.3 MOUNTING THE DRAWOUT OUTER CASE
•
The MD-3001 Drawout Relay mounts in the exact
same mounting holes as a standard MD-3000.
•
Remove the Drawout Inner Chassis from the outer
case.
•
Refer to Figure A-3. Place the outer case flush
against the backside of the panel so that the case
studs project through their respective holes.
•
The plastic outer flange is seated on the front of the
panel and is attached to the top, center and bottom
studs that protrude through the panel.
•
Use the #10-32 hex nuts and lock washers included
with the relay, to mount the unit on the panel.
A4.0 WIRING AND SETUP
ENSURE THAT THE INCOMING AC POWER
SOURCES ARE DISCONNECTED BEFORE
PERFORMING ANY WORK ON THE MD-3001
PROTECTIVE RELAY OR ITS ASSOCIATED
EQUIPMENT. FAILURE TO OBSERVE THIS
PRACTICE COULD RESULT IN EQUIPMENT
DAMAGE, SERIOUS INJURY AND/OR DEATH.
Refer to Figures A-4, A-5, A-6, and A-7 for the MD-3001
typical wiring diagrams. Note the following:
•
Direct wire connections to the terminal blocks must be
sizes #14 AWG to #10 AWG. The appropriate sized
spade and ring lugs can also be used to
accommodate the wires.
•
All contacts are shown in the de-energized position.
NOTE: All wiring must conform to applicable federal,
state, and local codes.
