M.C. MILLER JR-2 User manual
MAN090
Model JR-2
Current Interrupter
Operating Manual
(Revised August 19, 2011)
Catalog # 12830
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
2
Table of Contents
Topic
Page
Warranty
3
General
4
Capabilities
4
Features
4-5
Specifications
6-7
Panel Controls
8
Operations Overview
9
Installation of the Interrupter in
the Rectifier
9
AC/DC Current Carrying Limits
11
Example 1: Delayed Start –
Interruption Begins Later
12
Example 2: Intermediate Start –
Cycle Begins Now
13
Example 3: Extended Delayed
Start (Next Day)
15
Synchronizing a
Model JR-2
16
Maintenance
17
Repairs
18
Low Battery Indication
18
Supply Voltage Selection
18
Charging the Battery
19
Replacement Parts
Appendix 1: How to change the
voltage setting on the power entry
module to match the supply
voltage, and, how to change the
fuses (JR2 model with 3-pin
socket mounted on the back of the
unit)
20
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
3
Warranty
M.C. Miller Co., Inc. warranties each new instrument
manufactured and sold to be free from defects in material,
workmanship, and construction except for batteries, which
may be contained therein. When used in accordance with
this Operating Manual the unit will perform to applicable
specifications for a period of one year after shipment.
If examination by M.C. Miller Co., Inc. discloses that the
product is defective, then its obligation is limited to the repair
or replacement of the defective unit or its components at the
option of M.C. Miller Co., Inc.
M.C. Miller Co., Inc. is not responsible for products, which
have been subject to misuse, alteration, accident, or for
repairs not performed by M.C. Miller Co., Inc.
Instruments must be returned properly packed with the
transportation charge prepaid to:
M.C. Miller Co., Inc.
11640 US Hwy 1
Sebastian, Florida 32958
Return transportation charges will be F.O.B. factory. No
parts shall be returned without prior authorization, which
shall be furnished upon request.
The foregoing warranty constitutes M.C. Miller Co., Inc.'s
sole liability and is in lieu of any other warranty of
merchantability or fitness. M.C. Miller Co., Inc. shall not be
responsible for any incidental or consequential damages
arising from any breach of warranty.
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
4
General
The MCM Model JR-2 is a microprocessor controlled, high
current interrupter featuring a high stability, temperature
compensated time base. The JR-2 was specifically designed
for the interruption of multiple rectifier cathodic protection
systems in order to conduct synchronized instant off testing
for extended periods.
Capabilities
The JR-2’s capabilities include DC interruption in excess of 5
KW loads and AC interruption in excess of l0 KW loads
(Reactive). Also, multiple unit synchronous operation is
guaranteed for a normal five-day workweek. The JR-2 is
sync and program compatible with all other models of the
Model JR family of current interrupters.
Features
Synchronization with any number of Model JR
current interrupters;
Five functions - programmable from the front
panel keypad;
Night latch - automatically stops relay in closed
position when the STOP SET is programmed.
The operation resumes when the START SET time
is reached;
Relay Condition - Displayed as ON or OFF along with
a count down of time remaining in that condition;
Start Condition - Switch is Closed now and re-defined
To include STOP SET or Night Latch;
Self Diagnostic - Automatically performs a system
test at start up and displays Pass if the JR-2 is
ready to proceed;
An examination of the programmed parameters may
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
5
be done at any time by pressing the appropriate
function key;
Memory –The last entry made for each function is
Remembered by the JR-2 . There is no need to
re-program for each start up;
Synchronization - Multiple units may be synchronized
before or during operation;
Re-synchronization –The JR-2 calculates when
the relay should be switching, based on start time;
This allows the re-synchronization of an existing unit
or insertion of additional units during a test
in progress;
Charging System - A unique three-step system
provides faster recharging, longer battery life, and
temperature compensation. This allows for
indefinite float charging during storage;
State-of-Charge Indicator - This indicator changes
from RED to GREEN when 100% capacity
is reached;
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
6
Specifications
DISPLAY: 5-1/2-digit liquid crystal with battery and relay
condition annunciators. Character height: .5 in. Operating
temperature: -20 to +195 degrees F. (-30 to +90 C degrees.)
TIME BASE: 2 MHz Temperature Compensated Crystal
Oscillator, 0.5 Sec. per 24 Hr.
KEYBOARD: Sealed, Tactile feedback, 16 key
Arrangement: 5 function keys Time Set, Start Set, Stop Set
(6) On cycle, Off cycle, 10 digit keys: 0- 9, 1 Enter Key:
ENTER
CYCLE RANGE: .1 to 999.9 seconds, On Cycle and
Off Cycle.
AUTO START: Start Set: Programmable delayed Start from
1 minute to 24 hours, in one-minute increments.
AUTO STOP: Stop Set (6). Programmable Stop from
1 minute to 24 hours, in one-minute increments
NOTE: Always stops with respect to “Start Relay” switch
Position. (Open or Closed)
SYNCHRONIZATION: Multiple Unit capability, compatible
with all JR versions.
ACCURACY: Typically less than +/- .5 sec. over 24 hours
RELAY: Normally Closed Mercury Plunger
MAXIMUM RATINGS: CURRENT -
100 A @ 48 VDC 100 A @ 120 VAC
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
7
MAXIMUM RATINGS: VOLTAGE -
30 A @ 240 VDC 40 A @ 600 VAC
BATTERY: Sealed, rechargeable, 12 Volt, 7 A.Hr
BATTERY LIFE: Is dependent on the interruption duty
cycle. Examples:
4 sec On/1 sec Off: Lifetime = 50 hours
1 sec On/4 sec Off: Lifetime = 15 hours
Since power is required to hold the relay open in the case of
the JR2, battery lifetimes will be shorter for longer Off time
duty cycles.
SIZE: Exterior Dim. 10-5/8” x 9-11/16” x 6-7/8”
Metric Dim. 269.875 x 246.050 x 174.625 mm
WEIGHT: 14bs. Net weight. (6.4 Kg.)
NOTE: The JR-2 needs to be put in an Upright Position in
order for the unit to Work. The Mercury Relay will not work if
it is lying on its side. Once the JR-2 is programmed to the
proper setting you wish to set, at that time you may set the
JR in an Upright Position and press start set so it may
operate correctly. The level should be at the TOP of the
case.
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
8
Panel Controls
A. Battery Charging Indicator Light;
B. Power Switch;
C. Relay Starting Position Switch
D. Synchronizing Receptacle;
E. LCD Display Window;
F. Low Battery Indicator;
G. Rectifier Condition Indicator;
H. Display Area for Clock Time, Starting Time,
Countdown Timing and Settings for ON Cycle and
OFF Cycle;
I. Keyboard for Setting Times, ON Cycle, OFF Cycle
and Activating Clock.
Vero Beach~Florida~32960
Model JR-2
CURRENT INTERRUPTER
Open
POWER
On
On
CHARGER
START
RELAY
Off Closed
SYNC
Mercury Relay Must be
Upright in Order to Operate
CYCLE
OPEN
ENTER
3
1
7
45
2STOP
SET
89
CLOCK
SET START
SET CYCLE
CLOSED
ON
6
0
OFF
LOBAT
RELAY
ON OFF
B
A
C
D
E
F
G
H
I
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
9
Operations Overview
A. Turn Power Switch "ON";
B. Select Start Relay is Closed (Also applies to Stop or
Night Latch, i.e., Start Closed -Stop Closed;
C. Enter operating time requirements under the five
function keys;
D. Synchronize all units to be used, to each other;
E. Install units in system to be tested to include:
Observing polarity if DC is to be interrupted.
The JR-2 contains an EEPROM, which retains the last entry
made under the five function keys. Factory testing will leave
an existing program, which will be overwritten by the
next entries.
The uses for the JR-2 are too numerous to list. The following
examples will serve as both a set up (programming) and
typical use guide. These examples assume instant-off
testing of multiple rectifier cathodic protection on a structure.
Note: ALWAYS USE THE MILITARY TIME FORMAT
WHEN ENTERING TIME DATA.
FOR EXAMPLE: 18:00 INSTEAD OF 6:00 PM
Installation of the Interrupter in the Rectifier
In general, it is physically easier to interrupt across the taps
of the rectifier. In addition the tap location is best because
breaking AC causes less wear on the relay. This is due to
the AC crossing zero volts and extinguishing the arc,
whereas DC depends on the distance of the gap to
extinguish the arc. The next best location to interrupt is the
AC power supply. The DC side may also be interrupted at
the anode or structure leads (+) or (-) output of the rectifier.
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
10
When using the JR-2 to interrupt on the DC side, the
indicated polarities should be observed to reduce wear of the
plating on the plunger of the mercury relay.
Warning: Always observe the proper safety procedures
when working on electrical equipment. Turn off all live wires
before inserting the current interrupter.
.
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
11
AC/DC Current Carrying Limits
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
12
Example 1: Delayed Start –Interruption
Begins Later
The units will be put in place before the interruption cycle
begins. In other words, the units will be synched before the
Start cycle time has occurred
It is 7:00 in the morning and the JR-2's are in one location
ready to be synched. They will be installed in the rectifiers
before 8:00 am. At 8:00AM, the JR-2's will start their On / Off
cycle and remain cycling until 5:00PM the same evening. At
this time, the JR-2’s will shut the relay and wait until 8:00AM
the next morning before resuming interruption.
Test Requirements: On Cycle -2 seconds; Off Cycle -.5
seconds.
Work Schedule: Start at 8:00 A.M., Stop at 5:00 P.M., and
repeat for XXX days, as necessary.
The present time is 7 :00AM
Procedure - All Units Display Reading
1. Power Switch ON PASS
2. Start Relay-Closed PASS
3. Press START SET, 8,0,0, ENTER (8AM) 8:00
4. Press STOP SET (6),1,7,0,0 ENTER (5PM) 17:00
5. Press ON CYCLE, 2,0, ENTER (2 SEC.) 2.00
6. Press OFF CYCLE, 5, ENTER (0.5 sec) .50
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
13
7. Interconnect "SYNC" jacks on all units, daisy chain
fashion.
8. Press CLOCK SET, 7, 0,2 ENTER 7:02
9. When present time (your wrist watch) reads 7:02
Press 'ENTER' once on one unit only 7:02
10. At 7:02, all units will begin running as evidenced by a
flashing colon (:).
The sync cables may now be removed and the JR-2’s
distributed to their various locations for installation.
Testing may begin at 8:00 A.M.
Example 2: Immediate Start –Cycle Begins Now
The JR-2’s will be put in place after interruption cycle begins.
In other words, the units will be synched after the Start cycle
time has occurred.
It is 2:30 in the afternoon and the JR-2’s are in one location
ready to be synched. They will be installed in the rectifiers
later. The JR-2’s will start their On/Off cycle immediately and
remain cycling until 5:00PM in the evening. At that time, they
will shut the relay and wait until 8:00AM the next morning
before resuming interruption.
Test Requirements: On Cycle -2 sec.; Off Cycle -.5 sec.
Work Schedule: Start 8:00AM, Stop 5:00PM, and repeat for
XXX days, as necessary.
The present time is 2:30 PM
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
14
Procedure -All Units Display Reading
1. Power Switch ON PASS
2. Start Relay-Closed PASS
3. Press START SET, 8,0,0, ENTER (8AM) 8:00
4. Press STOP SET (6), 1,7,0,0, ENTER (5PM) 17:00
5. Press ON CYCLE, 2,0, ENTER (2 sec.) 2.00
6. Press OFF CYCLE, 5, ENTER (0.5 sec) .50
7. Interconnect "SYNC" jacks on all units, daisy
chain fashion.
8. Press CLOCK SET, 1,4,3,2. (2:32PM)
(press ENTER) 14:32
9. When present time (your wrist watch) reads 2:32
Press 'ENTER' once on one unit only 14:32
10. At 14:32, all units will display LOCh #
This is a countdown operation to show that the units are
performing a calculation. When the calculation is complete,
all the units will immediately commence cycling. Since the
relays are now in operation, try to maintain them in an
upright position during transport and installation.
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
15
Example 3: Extended Delayed Start (Next Day)
Test Requirements: Same as Example I.
Work Schedule: Testing to begin 8:00AM the next morning.
Present Time: 1:30PM
Procedure: With the following exceptions, follow Example 1.
Display Reading
1. Press START SET, 3, 2, 0, 0, ENTER 32:00
In short, add 24:00 to desired start time, eg,
31 :00 would be 7:00 A.M. plus 24 hours = 31 :00
Miscellaneous Features:
If STOP SET is not desired, (continuous cycling), program
STOP SET to an illegal time, eg, 24:01.
To create a '"MASTER" unit which never starts cycling,
program "STOP SET' to equal "START SET'
Correcting Keypad Entry Errors:
Press "The letter Ountil display reads 00:00, then enter the
correct numeric sequence.
EXAMPLE: 1,3,0 was entered for 1:30PM. Press the letter O
four times, and then press 1,3,3,0 Enter. The correct entry
reads 13:30.
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
16
Synchronizing a Model JR-2
Suppose there are five JR-2’s in the field and one is
accidentally turned off and needs to be restarted and
resynchronized. All the units could be brought back to a
single location, daisy chained together, and started as in
example 2. This procedure will work, but is rather inefficient.
Therefore, the JR-2’s are constructed so that any one of the
operating units may be used as a master to restart the failed
slave unit. Simply take the slave unit to the working master
location and follow the procedure below. The JR-2’s
automatically output a trigger pulse to the SYNC receptacle
once a minute when running.
Procedure:
1. Turn the slave unit to be resynched OFF,
and then ON.
2. Check or set the functions on the slave to the same
as those on the master. Press the function key on
both the master and the slave to display their
settings.
a. START SET;
b. ON CYCLE;
c. OFF CYCLE;
d. STOP SET;
e. START RELAY SWITCH CLOSED.
3. Press "CLOCK SET' on the slave and enter a time
which is a minute or two ahead of the MASTER.
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
17
4. Press "ENTER" and then connect the SYNC cable
when less than one minute remains between
"CLOCK SET' and the time shown on Master Unit.
Display the master time by pressing clock set on the
master.
5. Remove SYNC cable when the display shows some
activity, such as a flashing colon, or LOCh #.
6. The slave is now resynched and may be returned to
service.
NOTE: The above method may be used to synch the JR-2’s
one at a time as needed. For example, there were 6 JR-2’s
to be installed over a long distance by one individual. One
JR-2 could be started and kept in the truck as a master. At
each location, a single JR-2 could be started and installed
using the above method.
Maintenance
A few routine maintenance steps will insure the maximum
life for your JR-2.
A. Maintain the battery in as near a fully charged state
as possible;
B. Never operate the relay in a less than
vertical position;
C. Observe polarity when interrupting DC;
D. Provide adequate ventilation when interrupting
currents in excess of 20-25 AMPS.
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
18
Repairs
With the exception of the battery and the relay, there are no
field replaceable parts in the JR-2. No one other than
qualified electronic technicians should attempt servicing the
JR-2. Contact the M. C. Miller Co., Inc. if a problem arises.
Low Battery Indication
When the battery has discharged to a factory-set level, a
LO BAT indication will display in the upper left portion of the
display window. Approximately two hours of operating time
remains when the indicator displays.
Supply Voltage Selection (for charging and/or
powering the unit)
For the JR2 model with the 3-pin socket mounted on the
front of the unit (case handle side):
The input voltage (supply voltage) setting is established via
the fuse selector by the customer. A small bag with the fuse
and the fuse holder is attached on the outside of the case
with instructions provided on how to position the fuse in
order to establish a particular voltage setting.
For the JR2 model with the 3-pin socket mounted on the
back of the unit:
Please see Appendix 1 below (pages 20-27) [How to change
the voltage setting on the JR2’s power entry module to
match the supply voltage, and, how to replace the fuses]
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
19
Charging the Battery
A sealed lead acid gel-cell battery furnishes power for
the JR-2.
The front panel indicator, displaying state-of-charge, will be
RED during the charging stage. When the battery is fully-
charged, the charging indicator will turn GREEN and remain
GREEN through the float stage. Charging may take place
during operation or storage, periodically, or on a continuous
basis. If continuous charging during storage is performed,
the circuit will automatically maintain a full charge,
regardless of the temperature.
The battery charging time will depend on the status of the
battery prior to beginning the charging process. Typical
charging times (for GREEN light observation) are as follows:
Fully-discharged battery: approx. 11 hours
40% discharged battery: approx. 5 hours
As an example, the battery in a unit that has been run for a
total of 16 hours in a 0.7sec ON/0.3sec OFF switching mode
will be approximately 40% depleted and will require approx.
5 hours to re-charge to full capacity.
Replacement Parts
Battery 12 Volt, 7A.Hr Part # BATOO8
Sync Cable Assembly Part # SUBO26
3-Conductor Line Cord Part # CONO14
Power cable Assembly Part # SUB577
MCM JR-2 Current Interrupter
11640 US Hwy 1, Sebastian FL 32958
Tel: 772-794-9448 ~ Fax: 772-589-9072
Instruments and Equipment for the Corrosion Engineer
20
Appendix 1
How to change the voltage setting on the JR2’s
power entry module to match the supply voltage, and,
how to replace the fuses
WARNING: Disconnect the external AC power supply
before changing the input voltage setting or
replacing the fuses
Changing the voltage setting to match the supply voltage:
Your JR2 current interrupter will have been shipped to you
with an input voltage setting appropriate for your country.
However, since it is extremely important that the input voltage
setting match the AC supply voltage applied to the unit, for
charging and/or powering purposes, it is critical that you
check to make sure that the setting is correct for your
application.
To do so, examine the panel directly above the 3-pronged
socket. The input voltage setting will be indicated by
whichever hole is occupied by the plastic indicator (100V,
120V, 230V or 240V).
If the input voltage setting is not appropriate for the voltage
you will be supplying to the unit, please follow the instructions
below to change to the correct setting:
Example: Changing from a 120VAC setting to a 240VAC
setting.
The 120VAC setting is indicated in Figure 1.
Step 1: Gently pry open the panel door using a small flat
This manual suits for next models
1
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