Hitachi 152SO Guide

SM 5924
1000 Technology Drive, Pittsburgh, PA 15219
645 Russell Street, Batesburg, SC 29006
PN-152SO
Switch Overload Relay
STS USA Part No.
N322522-001
N322522-802
Installation
Operation

PN-152SO Switch Overload Relay
Copyright 2019 SM 5924 Rev. 3, March 2019

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 i
Proprietary Notice
This document and its contents are the property of Hitachi Rail
STS USA, Inc. (formerly known as Union Switch & Signal Inc.,
and hereinafter referred to as "STS USA"). This document is
furnished to you on the following conditions: 1.) That no
proprietary or intellectual property right or interest of STS USA
is given or waived in supplying this document and its contents
to you; and, 2.) That this document and its contents are not to
be used or treated in any manner inconsistent with the rights of
STS USA, or to its detriment, and are not to be copied,
reproduced, disclosed or transferred to others, or improperly
disposed of without the prior written consent of STS USA.
Important Notice
STS USA constantly strives to improve our products and keep our customers apprised
of changes in technology. Following the recommendations contained in the attached
service manual will provide our customers with optimum operational reliability. The data
contained herein purports solely to describe the product, and does not create any
warranties.
Within the scope of the attached manual, it is impossible to take into account every
eventuality that may arise with technical equipment in service. Please consult an STS
USA local sales representative in the event of any irregularities with our product.
STS USA expressly disclaims liability resulting from any improper handling or use of our
equipment, even if these instructions contain no specific indication in this respect. We
strongly recommend that only approved STS USA spare parts are used as
replacements.

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 ii
Revision History
Rev. Date Nature of Revision
*
November, 1980
Original Issue
*
March, 2000
Revision
2 November 2003
Revised to indicate that part number
N322522-001
3
March 2019
Hitachi Rail STS Branding
* Revisions were identified by date only; no numbers were assigned to
revisions.

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 iii
Table of Contents
1. INTRODUCTION ...............................................................................................................................1-1
1.1. Introduction ............................................................................................................................... 1-1
1.2. Shock Indicators ....................................................................................................................... 1-1
1.3. Mechanical Specifications ........................................................................................................ 1-2
1.4. Electrical Specifications ............................................................................................................ 1-2
2. INSTALLATION.................................................................................................................................2-1
2.1. General ..................................................................................................................................... 2-1
2.2. Mounting Base.......................................................................................................................... 2-1
2.3. Relay Indexing .......................................................................................................................... 2-1
2.4. Receptacle Contact Springs ..................................................................................................... 2-2
2.4.1. Old-Style Base Only (N398314) ...................................................................................2-2
2.4.2. Improved One-Piece Base Only (N451376-0302)........................................................2-2
2.4.3. Installing Wires in Receptacle Contact Springs............................................................2-3
2.5. Relay Insertion.......................................................................................................................... 2-4
3. FIELD MAINTENANCE .....................................................................................................................3-1
3.1. Introduction ............................................................................................................................... 3-1
3.2. Periodic Performance Test ....................................................................................................... 3-1
3.2.1. Cleaning........................................................................................................................3-1
3.2.2. Service Requirements ..................................................................................................3-1
4. SHOP MAINTENANCE .....................................................................................................................4-1
4.1. Adjustment and Calibration....................................................................................................... 4-1
4.1.1. Operating Relay ............................................................................................................4-1
4.1.2. Stick Relay ....................................................................................................................4-1
4.1.3. Preliminary Calibration..................................................................................................4-2
4.1.4. Internal Wiring...............................................................................................................4-3
4.1.5. Final Calibration ............................................................................................................4-3
4.1.6. Service Recommendations...........................................................................................4-5
5. TECHNICAL SUPPORT....................................................................................................................5-1
6. PARTS LIST ......................................................................................................................................6-1
6.1. PN-152SO Relay (Complete) ................................................................................................... 6-1
6.2. PN-152SO PARTS LIST (Unit “A”) ........................................................................................... 6-5
6.3. PN-152SO Parts List (Unit “B”)................................................................................................. 6-8
6.4. PN-152SO Base and Test Plugs Parts List .............................................................................. 6-9
6.5. Parts List For New Mounting Base For PN-152SO Relays .................................................... 6-11
List of Figures
Figure 2-1. Typical Plug-in Relay and Mounting Base.............................................................................. 2-1
Figure 2-2. Receptacle Contact Springs Installed .................................................................................... 2-3
Figure 4-1. Circuit for Preliminary Calibration ........................................................................................... 4-2
Figure 4-2. Wiring, Facing the Front of the Relay ..................................................................................... 4-3

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 iv
Figure 4-3. Final Calibration...................................................................................................................... 4-4
Figure 6-1. PN-152SO Internal Parts Location (Sheet 1 of 3) (Dwg. D66000-33).................................... 6-3
Figure 6-2. PN-152SO Part Details (Unit “A”) ........................................................................................... 6-7
Figure 6-3. PN-152SO Part Details (Unit “B”) ........................................................................................... 6-8
Figure 6-4. PN-152SO Base and Test Plugs .......................................................................................... 6-10
Figure 6-5. New Mounting Base for PN-152SO Relays.......................................................................... 6-12
List of Tables
Table 1-1. Electrical Specifications ........................................................................................................... 1-2
Table 4-1. Electrical Adjustments and Calibration .................................................................................. 4-12
Table 5-1. Parts List References for PC-250B Code Following Vital Relay ............................................. 5-1
Table 5-2. PC-250B Code Following Vital Relay Main Assembly Parts List (see Figure 5-1)................. 5-2
Table 5-3. Parts List for Operating Unit (Item 11) Used on PC-250B Code Following Vital Relay
(see Figure 5-2) .................................................................................................................... 5-5
Table 5-4. Parts List for Contact Assembly Used on PC-250B Code Following Vital Relay
(see Figure 5-1) .................................................................................................................... 5-7
Table 5-5. Contact Assembly Section Parts List....................................................................................... 5-9
Table 5-6. Old Style Mounting Base for PC-250B Relays Parts List ......................................................5-10
Table 5-7. Improved Mounting Base (N438689-003) for PC-250B Relays Parts List ............................ 5-12

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 1-1
1. INTRODUCTION
1.1. Introduction
In the PN-150 line of relays the PN-150SO is the equivalent of the ORP-66 D.C. switch
overload relay. It is furnished primarily for the overload protection of high voltage D. C.
switch machines. This relay can be used also to protect low voltage D. C. switch
machines under the same current conditions. This relay, with a different thermal
resistor, can be furnished to match a motor with another D. C. current range.
The operating relay coil, paralleled by a thermal resistor, is in series with the motor.
When the motor current becomes excessive, the operating relay picks up. This picks up
the stick relay, which then releases the operating relay and deenergizes the switch
control relay, thereby opening the motor control circuit.
The thermal resistor has a high temperature coefficient of resistance, so that with
excessive motor current, its resistance will increase giving a longer cut-out time for a
lower current and a shorter cut-out time for a higher excessive motor current.
1.2. Shock Indicators
WARNING
Any relay showing shock indicator activation should be sent
to the shop for inspection before placing the relay into
service. Failure to assure proper function of this relay could
result in severe personal injury or death.
The shock indicator (P/N J680167-0012) shows red when the relay has been subjected
to shock in excess of a safe level (i.e., dropped) during shipment or transport. This is an
indication that the relay may have mechanical damage and may not meet electrical
specifications.
The relay should be opened and visually inspected for damage (i.e., kinked springs).
Mechanical settings should be checked, recalibrated, and tested according to
specifications by a qualified individual.

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 1-2
1.3. Mechanical Specifications
The mechanical specifications shown in Table 1-1 are common to all PN-152SO relays
covered in this manual.
Table 1-1. Mechanical Specifications
Parameter
Value
Dimensions
Height
7-1/16” (17.93 cm)
Width
2-7/16” (6.19 cm)
Depth
8-3/8” (21.27 cm)
Temperature
-40°F (-40°C) to +185°F (85°C)
Indexing
2201, 2202
Weight
4.0 Lbs. (1.814 kg.)
Mounting Base
N398314 (Old-Style)
N451376-0302 (New-Style) - 9 oz.
Mounting Base
Dimensions
Height
7-15/16” (20.1 cm)
Width
2-7/16” (6.19 cm)
Depth
2-7/16” (6.19 cm) - (Old-style Base)
1-25/32” (4.5 cm) - (New-style Base)
1.4. Electrical Specifications
The electrical specifications shown in Table 1-2 are common to all PN-152SO relays
covered in this manual.
Table 1-2 -Electrical Specifications
Part No.
Coil Resistance
(Ohms)
Thermal
Operating Time (+/- 10%)
N322522
Oper.
Stk.
Amps
Sec.
Amps.
Sec.
-802
5.0
750
.046
13
5
15
3
-001
5.0
750
.030
13
10
15
6

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 2-1
2. INSTALLATION
2.1. General
Relays plug directly into a mounting base that is secured to a rack. See Section 2.5 for
proper relay insertion.
2.2. Mounting Base
Secure the mounting base directly to the rack using the hardware furnished. All wiring
terminates at the rear of the mounting base to solderless terminals (contact
receptacles). Mounting base details are shown in Appendix A.
2.3. Relay Indexing
Relays are factory equipped with indexing pins to prevent insertion of an incorrect relay
into a mounting base. Each relay is accompanied by an indexing plate that is applied to
the mounting base at the time of initial installation. A typical plug-in relay with indexing
pins and base with corresponding indexing plate are shown in Figure 2-1.
The following data defines the indexing established for relays covered by this manual.
1. The index code always consists of four digits (such as 0001, 0002 or 0101). The
index code is used for both the relay and the indexing plate on the mounting
base.
Figure 2-1. Typical Plug-in Relay and Mounting Base
4C5.0002.00
INDEXING PINS
INDEX PLATE
RELAY
MOUNTING BASE
0123456789

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 2-2
2. The index codes for each relay can be determined from the relay part number
and its suffix that is marked on the nameplate attached to the front of the relay.
The first two digits of the index code are the last two digits of the part number,
and the second two digits of the index code are the last two digits of the suffix.
The index number should agree with the placement of the indexing pins in the
numbered vertical rows on the back of the relay, starting with the top pin and
reading down.
3. The index code for each mounting base is determined by the placement of the
holes in the numbered vertical rows of the large white nylon indexing plate that is
affixed to the front of the mounting base. This indexing plate should not be
removed from the mounting base unless it is damaged or the indexing is to be
purposely changed to accommodate a relay of a different part number. Discard
the indexing plate that comes in a bag tied to the handle of all new relays, unless
it is needed for replacement or a damaged indexing plate or for application to a
new mounting base.
WARNING
Never drill new holes in a base indexing plate that will permit
application of relays with different part numbers. Never
change indexing pins on the back of a relay unless it is being
converted to a new part number, otherwise a hazard will be
created that may compromise safety circuit functions.
2.4. Receptacle Contact Springs
2.4.1. Old-Style Base Only (N398314)
The N398314 mounting base normally will be equipped with the required quantity of
J680165 solderless receptacle contact springs and will accommodate one or two #14 or
#16 wires. It can, however, be equipped with receptacle contact springs for one or two
#10 or #12 wires (J680181), or for one or two #18 or #20 wires (J680179). Make certain
which type of solderless receptacle contact springs accompanies the mounting base
before proceeding with their installation.
2.4.2. Improved One-Piece Base Only (N451376-0302)
The new one piece mounting base with hardware includes a full complement of
receptacle contact springs (M451142-2702) to accommodate one or two #14-#16 wires,
mounting fasteners and tags. It can, however, be equipped with receptacle contact
springs for one or two #10-#12 wires (M451142-2703), or for one or two #18-#20
(M451142-2701). Make certain which type of solderless receptacle contact springs
accompanies the mounting base before proceeding with their installation.
Each solderless receptacle contact spring should be inspected for physical damage
before proceeding with installation.
The following is recommended when installing solderless receptacle contact springs
after crimping wires:

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 2-3
1. Receptacle contact springs must be inserted into the base with the lock side
down or lanced tab up (refer to Figure 2-2).
2. Make certain that the lanced tab is slightly compressed as the receptacle contact
spring is inserted along the top of the cavity. The lanced tab could have been
bent during handling and, therefore, would not provide the required contact
pressure after the relay is inserted. If the lanced tab does not touch, pull it up
slightly using fingers or a suitable tool.
3. After insertion, pull firmly on the wire to make certain the receptacle contact
spring is locked in the cavity.
Figure 2-2. Receptacle Contact Springs Installed
2.4.3. Installing Wires in Receptacle Contact Springs
Use the following procedure to ensure a good electrical and mechanical connection
between the conductor wire and the receptacle contact spring. Table 2-1 identifies the
correct crimping tool to be used when installing wires in receptacle contact spring.
Table 2-1. Crimping Tools
Crimping
Tool
Wire Size
Old-style Receptacle
Contact Spring
Improved Base Receptacle
Contact Spring
J397138
#10/#12 AWG
J680181
M451142-2703
J397139
#14/#16 AWG
J680165 (Standard)
M451142-2702
J397188
#18/#20 AWG
J680179
M451142-2701
1. Strip 3/16 in. (0.187 in. or 0.47 cm.) of insulation from the end of the wire.
2. Place the receptacle contact spring into the jaws of the proper crimping tool.
When using only one terminal of any wire size, use the shortest terminal.
RECEPTACLE
SPRING
CONTACT
RECEPTACLE
SPRING
CONTACT
LOCK SIDE LOCK SIDE
OLD MOUNTING BASE IMPROVED MOUNTING BASE
4C5.0003.00

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 2-4
3. Partially close the crimping tool jaws against the receptacle contact spring to hold
it in place. (Do not crush the receptacle contact spring barrel at this time.)
4. Insert the stripped end of wire all the way into the receptacle contact spring
barrel. Squeeze the tool handles until crimping is completed and the jaws
release. When using both terminals, it is more convenient to attach the first wire
to the longest terminal. This ensures that a second lead may be attached to the
receptacle contact spring at a later time.
5. Remove the crimped receptacle contact spring from the tool and inspect the
connection. Make certain that the wire is flush with the crimped barrel and that
there are no loose strands of wire.
2.5. Relay Insertion
Orient the relay to the mounting base with the name plate right side up; then plug the
relay into the base. The relay should be pushed firmly against the mounting base while
depressing the latch rod. After the relay is completely seated in the base, release the
latch rod, and pull on the handle to ensure that the relay has locked in place.

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 3-1
3. FIELD MAINTENANCE
3.1. Introduction
This section provides the necessary periodic preventive maintenance procedures that
must be performed to ensure continuous, proper, and efficient operation of the PV-250
style relays covered in this manual. Field maintenance covers periodic inspections and
performance tests.
3.2. Periodic Performance Test
3.2.1. Cleaning
Before inspecting and testing the relay, if necessary use a soft cloth to clean the exterior
to remove any dirt or dust that may have collected. A safe cleaning solution of alcohol
and water or common laundry detergent may be used for removal of accumulated dirt,
grease, etc.
3.2.2. Service Requirements
3.2.2.1. General
All PN-152SO relays must be inspected and tested at least every four (4) years. The
tests (see Table 4-2) and inspections are to include: pick-up time at given current; visual
inspection of contacts for damage, misalignment, corrosion or other contamination of
parts; loose parts inside of the cover; a broken seal; and a cracked or broken cover.
Relays not passing the above-stated tests and inspections must be replaced and not
returned to service until the operating characteristics and conditions are in accordance
with STS USA specifications.
3.2.2.2. In-Service Test
It is recommended that track relays in service be removed from service for shop repairs
when the calibration values are out of specification.
3.2.2.3. Test Procedures
Test the operating characteristics of the PN-152SO style relays as described in Section
4.1.5 in this manual.

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 3-2

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 4-1
4. SHOP MAINTENANCE
4.1. Adjustment and Calibration
4.1.1. Operating Relay
a. The air gap between the armature and the core should be between 0.007 to
0.010 inch.
b. The armature stroke at the free end of the armature insulation should be 0.105 ±
0.003 inch.
c. The two load springs should be adjusted to exert a pressure of approximately 7
grams each on the armature in the deenergized position. This pressure may be
changed as required to meet relay calibration values.
d. The heel spring should exert a pressure of approximately 13 grams against the
armature in the deenergized position.
e. The front contact spring should have an initial pressure of approximately 10
grams against its stop, measured at the contact tips, and should have an opening
of approximately 0.070 inch with the relay deenergized.
4.1.2. Stick Relay
a. The air gap between the armature and the core should be approximately 0.004
inch.
b. The armature stroke at the free end of the armature insulation should be 0.080 ±
0.002 inch.
c. The continuity contact should be adjusted as follows:
1. The front contact (lower) spring should be adjusted to exert a pressure of
from 10 to 15 grams on the armature in the deenergized position.
2. The opening between the front contact and the heel (upper) spring should be
from 0.020 to 0.025 inch with the armature in the deenergized position. At the
same time the heel spring pressure should be adjusted so that the back
contact tip just touches its lower stop and the upper stop should be adjusted
to just touch the heel spring.
3. Adjust the back contact opening to be from 0.015 to 0.020 inch with the
armature in the energized position by bending the loop at the end of the back
contact spring.
4. Adjust the back contact spring to exert an upward force of from 20 to 25
grams against the lower stop with the armature in the energized position.
Recheck the heel spring pressure.
5. With the armature in the energized position and all adjustments completed,
the opening between the back contact buttons and the lower stop is an
approximate measure of the mid-stroke overlap of the contacts. This should
be at least 0.010 inch.

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 4-2
4.1.3. Preliminary Calibration
The Operating and Stick relays should be individually calibrated to meet the limits given
in Table 4-1. With the relays disconnected, this is no problem. If the relays are wired,
they can be calibrated by temporarily opening the thermal resistor circuit at one terminal
and testing in a circuit as shown in Table 4-1.
Table 4-1. Preliminary Calibration Values
Relay Ohms
Min. Drop
Away
Pick-Up and Working
Min.
Max
Operating, N398329
5.0
0.20 V.
0.95 V.
1.0 V.
Stick, N398335
750.0
0.90 V.
8.0 V.
NOTE
When calibrating the stick relay, the operating armature must
be picked up manually to close the front contact.
Figure 4-1. Circuit for Preliminary Calibration
The load springs and front contact heel of the Operating relay and the front contact
spring of the Stick relay may be given a slight readjustment of their pressures if
necessary to meet the specified pick-up values.
a. Drop-Away - Each Style “L” relay shall be given a charge of four times the pick-
up value and the current, then gradually reduced until the armature drops away,
opening the front contact.
b. Pick-Up and Working - After the drop-away reading, the energizing circuit shall
be opened for one second. Then current of the same polarity shall be applied
again and gradually increased until the armature is attracted and the front contact
made. This is the Pick-Up and Working Value; and at this energization, the
armature shall move to the full stroke position.
REAR VIEW OF PN-152SO RELAY
MOUNTING BASE
OPER
S.P.D.T.
SWITCH
STICK
V
HV+
HV- WDC-
DC+
+
_
11C
12C 12B 12A
11A
4C5.0042.00

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 4-3
c. The air gap between the end of the core and the Operating relay armature should
not be reduced below 0.004 inch.
4.1.4. Internal Wiring
The internal wiring should be as shown in Figure 4-2.
4.1.5. Final Calibration
This is a test of the complete overload relay including the thermal resistor connected
across the operating relay coil.
Figure 4-2. Wiring, Facing the Front of the Relay
Final calibration should be made with the relay cover applied to give normal functioning
of the thermal resistor. After a given test the thermal resistor must be permitted to cool
before the test is repeated.
Test the relay in a circuit in accordance with Figure 4-3.
THERMAL
RESISTOR D
#1 #1
#2 #2
RELAY "A" RELAY "B"
OR ORS
(11A)
(12A)
DC+
DC-
(11B)
(12B)
W
HV+
HV-
(11C)
(12C)
S
4C5.0043.00

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 4-4
Set resistor R-2 to provide 0.013 ampere to pick-up stick relay. Momentarily close
switch “S” to position “1” to pick-up the Heavy Duty relay, which will be held energized
over its own front contact.
Then throw switch “S” to the position “2” to energize overload relay. By adjusting R-1,
set the “overload” current at the value specified in Table 4-2. At this current value the
operating relay should pick-up within 10% of the time value specified in Table 4-2. A
small adjustment of the operating time can be obtained by reducing or increasing the
distance between the turns of the thermal resistor.
Figure 4-3. Final Calibration
When the operating relay picks up, it energizes the stick relay, which in turn releases
the heavy-duty relay. When the heavy-duty relay drops out, it interrupts the overload
current circuit to the operate relay. (Heavy duty release interrupts the overload current
to the operate relay, which drops out.)
Successive tests of operating time must be made. Allow sufficient time for the thermal
resistor to return to room temperature between tests.
REAR VIEW OF PN-152SO RELAY MOUNTING BASE
11C 11A
HV+ DC+
12C
HV-
12B
WDC-
A
R-1 R-2
A
"OPERATE"
D.C. AMMETER
S1
2
"STICK"
D.C.
AMMETER
10 T0 12 V.D.C.
+_
1F
1H
2F 2H
12V
COIL
HEAVY
DUTY
RELAY
10 OR 12V
RELAY WITH 2
FROT CONTACTS
CAPABLE OF
INTERRUPTING
20 AMP AT
12VDC
NOTE: R-1 RESISTOR MUST BE
CAPABLE OF CARRYING
20 AMPS INTERMITTENTLY.
R-2 RESISTOR IS TO ADJUST
CURRENT TO 0.013 AMPS.
12A
4C5.0044.00

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 4-5
4.1.6. Service Recommendations
Relays should be checked periodically in service to assure they give the desired delay
times. This may be done by obstructing the switch points, measuring the current at
which the clutch slips and noting the time it takes for the relay to function.
For accurate measurement of time for the relay to operate, about five minutes should be
allowed for the thermal resistor to cool. In no case should another operation be tried
with less than six seconds cooling time or the relay may not have sufficient motor surge
current protection.
When adjusting or working on a switch machine, apply a jumper between terminals HV+
and HV- to shunt out the thermal resistor. Of course, the jumper must be removed for
normal circuit functioning.
Switch machine clutch slippage should be maintained at approximately 13 amperes. It
the clutch slippage current is excessively low, the overload relay will not function and
might be damaged.
Table 4-2. Final Calibration Values
Relay P/N
Thermal Resistor
Operating Time
P/N
Nom. Ohms
@Amps
Sec.
@Amps
Sec.
N322522-802
N436521
.046
13
5
15
3
N322522-001
N398311
.030
13
10
15
6

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 4-6