INSTALLATION AND MAINTENANCE INSTRUCTIONS
JOSLYN P/N 1266-85
AC SURGE PROTECTOR
240/480 VAC CENTER GROUNDED SINGLE PHASE OR
240 VAC, 3φ CORNER GROUNDED DELTA
Danaher Power Solutions
5900 Eastport Blvd., Bldg. V
Richmond, VA 23231-4453
Telephone (804) 236-3300
Facsimile (804) 236-4040
Excellence in Systems Protection
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TABLE OF CONTENTS
Section
Title
Page
I.
Specifications
2
II.
Installation
3
III.
Theory of Operation
4
IV.
Maintenance
5
Figure 1
Dimensions
7
Figure 2
Connection Diagram
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I. SPECIFICATIONS
Joslyn P/N 1266-85
AC Surge Protector
APPLICATION:
240/480 VAC, 1φ, 3 Wire plus Ground, or 240
VAC 3φ Corner Grounded Delta
Voltage Rating Line-to-Neutral
240 VAC
Power Rating
Unlimited
Protector Modes
L-N, L-G, N-G
Varistor Voltage, @ 1 mA DC, Line-to-Neutral
420-520 VDC
Clamping Voltage, (L-NG), at Arrester Terminals
with
5 kA 8/20 µs
10kA 8/20 µs
20kA 8/20 µs
800 V
920 V
1300 V
Minimum Life with 10 kA, 8/20 µsec, per line
2,000 Operations
Maximum Surge Current Rating, per line
100 kA 8/20 µs*
Operating Temperature Range
-40° C to +65° C
Maximum Operating Altitude
5,000 Meters
Power Consumption
Less Than 9 Watts
Remote Monitoring Circuit Contact Rating
3 A @ 240 VAC
3 A @ 32 VDC
*Surge Currents greater than 28 kA 8/20 µs may require replacing the fuse to restore arrester function.
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II. INSTALLATION
Joslyn P/N 1266-85
AC Surge Protector
The Joslyn AC Surge Protector P/N 1266-85 is intended for installation on power systems of 240/480V RMS, 5060Hz, single phase, center neutral, 3 wires plus ground, or 240V RMS, 3 phase, 3 wire corner grounded delta
systems, unlimited kVA rating.
Location: Locate the protector on or as close to the service entrance cabinet as possible. It should be shortnippled directly to the service cabinet and located so that the wires used to connect to the bus are as short as
possible. (The inductance of the wiring, about 1 micro Henry per meter, results in every foot adding about 300
volts to the suppression voltage of the protector on a typical 10kA lightning surge.)
Mounting: The protector may be mounted in any position using the four .31" mounting holes. See Figure 1 for
protector dimensions. The protector may be mounted above, below or beside the service cabinet. Drill or punch a
hole in the protector housing for the conduit, selecting one of the possible locations shown in Figure 1.
Connections: Use the shortest and straightest path possible to connect the protector to the power system,
avoiding sharp bends or loops in the wire. Twist the wires together if possible. See Figure 2 for connection
diagram. The protector should be connected directly to the bus on the load side of the main service disconnect. If
no tap is available on the bus, it may be connected to a 60 Amp breaker.
The wire size for the power circuit connections should be AWG No. 4 to 2/0. Size AWG No. 2 is typically used.
Measure the voltage between all lines (phases) and the neutral. The voltage must be between 212 and 254 volts;
if it is not, correct the wiring before connecting the protector.
Connect the green Ground wire to the terminal marked "Ground" inside the protector cabinet.
Connect the white Neutral wire to the terminal marked "Neutral" on the metallic circuit board.
Connect the 2 "hot" wires to the isolated terminals marked "Line 1" and "Line 2" in any sequence.
Remote Sensing Circuit: The terminal blocks, labeled "1, 2, 3", on top of the relay circuit assembly provide
connections to 2 sets of unpowered sensing relay contacts. If a closing of relay contacts is desired when a fuse
opens, connect sensing wires to terminals 1 and 2. If an opening of relay contacts is desired when a fuse opens
up, connect sensing wires to terminals 2 and 3. See Figure 2 for details.
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III. THEORY OF OPERATION
Joslyn P/N 1266-85
AC Surge Protector
The purpose of the Joslyn AC Surge Protector, P/N 1266-85, is to provide voltage clamping to neutral whenever
instantaneous (surge) line-to-neutral voltage on any phase exceeds a level of approximately 470 volts peak. The
protector responds in nano- seconds, and automatically restores itself to normal condition after termination of the
surge condition. No power-follow occurs and the disturbance to the line voltage is minimal.
Each line of the protector has two protector modules, a fuse, and two monitoring circuits. One protector module on
each line is connected to neutral and the other module to ground. Refer to connection diagram of Figure 2.
Each protector module consists of several metal oxide varistors (MOV) in parallel. Each MOV has its own fuse.
The fuse will blow before the maximum surge current rating of the MOV is exceeded. The fuses also help to
balance the current distribution among the MOVs.
A replaceable fuse is provided for each phase so as to disconnect the protector module from the power source in
the event of a continued overvoltage or excessive surge current. The fuse may be blown by surge currents
exceeding 28,000 amperes. The fuse can be removed to disconnect the protector from the line for test purposes
without having to turn off the power to the equipment the protector is protecting. In addition to the replaceable fuse,
each protector module is internally fused in case of failure of the clamping components in a shorted mode.
Each line of the protector has a monitoring circuit with an indicator light on the cover of the protector enclosure.
When the protector is in operating condition, the light is on. Each line also has a relay connected to a terminal strip
for connecting to external alarm circuits. Two sets of terminals are provided. Terminals 1 and 2 on the terminal
strip provide connections to the open contacts of the relays of both lines in parallel. Terminals 2 and 3 provide
connections to the closed contacts of the relays of both lines in series.
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IV. MAINTENANCE
Joslyn P/N 1266-85
AC Surge Protector
The Joslyn AC Surge Protector, P/N 1266-85, requires no scheduled maintenance. There are no moving parts
except the relays in the monitoring circuit. There are no adjustments to make. Simple electrical tests will indicate
the condition of the unit.
The lights on the cover and the remote alarm circuits are used to monitor the condition of the protector. Proper
operating conditions are indicated by the lights being on. If the lights are off or a remote alarm signal is obtained,
one or a combination of the following conditions exists:
a)
b)
c)
d)
e)
f)
g)
The LEDs have failed.
The system voltage is off.
The external fuses have opened.
Internal fuses in modules have opened.
Resistors in the lamp circuit have opened.
Relays are defective.
The protector is defective.
If one or more lights are off - 1. Check the system voltage.
2. Check the fuse.
If the system voltage is on, the fuse is intact, and the light is still not on, or a remote alarm signal is obtained:
1. Measure voltage between monitoring wire terminal (located on the PC board) of corresponding Line 1
or 2 and neutral. Voltage must read same as supply voltage. If no voltage can be measured, both
modules may be defective and should be replaced.
2. If modules are operational, the light is on, but a remote signal is obtained, replace the relay.
3. If light still is not on, a series limiting resistor or diode for the light may be open. Check resistors for
continuity and value.
If the fuse is open - 1. Test the protector modules for DC clamping voltage as noted in the next section.
2. If the module is within specification limits, replace the fuse.
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The following test will determine the condition of the protector modules:
CAUTION
It is desirable to test the protector with the power off. If this is not practical, extreme caution must be observed
when testing with power on and the fuses removed. Hazardous voltages are present at the line terminals.
Varistor Voltage Test
The varistor voltage of the Protector Modules may be tested as follows:
a) Disconnect power.
b) Remove the fuses and relays.
c) Use a suitable Surge Protector Test Set, such as Joslyn Model 4010. Connect the negative test leads
to the line terminal of the module and the positive test lead to the neutral terminal of the module.
Operate Test Set in accordance with instructions and read the displayed value. This is the Varistor
value.
The following varistor voltage values are considered acceptable:
1. Factory specification for new Protector
420 to 520 VDC
2. Protector in Use
410 to 540 VDC
Replace Protector Modules if the Varistor Voltage is below 410 V.
To replace a Protector Module, proceed as follows:
a) Disconnect power.
b) Remove fuses.
c) Disconnect monitoring lead of module to be removed from terminal block.
d) Remove 10-32 Screw from protector module neutral bracket and chassis.
e) Loosen 8-32 Nuts on top of protector module. Remove neutral bracket.
f) Slide module away from fuse terminal.
To install a new Protector Module the steps above are reversed.
Replaceable Parts:
1. Protector Module: Joslyn P/N 72116
2. Fuse: Buss P/N FRN-R-60, Joslyn P/N 63539
3. Relay: Omron MY2-AC240, Joslyn P/N 51516
Optional Equipment: Joslyn Model 4010 Surge Protector Test Set
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FIGURE 1
DIMENSIONS
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CONNECTION DIAGRAM
FIGURE 2
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