RS7 Series Instruction Manual - Benshaw

BENSHAW
RS7 Series
INSTRUCTION MANUAL
I t’ F S I.) I t .
R
P
• ,! ‘f •
4
7 8’
FAX ft 4 2)487-4201
for
SOLID STATE
SQUIRREL-CAGE
INDUCTION MOTOR STARTERS
with DC INJECTION BRAKING
R R ft IX 4? F OPOWIC’4
ONTtP!’ A11t’A PI’
S 9 3:1 5 3
FAX#(5 1 9335 3627
REV2
RS71M-093088
‘j4h WF ‘- ‘Wfl( .
‘‘)P! (fç!,!!j ?M .
•‘4 464 H505
FAX U (604 46 4? 24

TABLE OF CONTENTS
General i
DC Injection Braking Specification...... 1
Pre-Startup Inspection............... 1
Power Assembly Technical Data..... 1
Connection Procedure for Squirrel-Cage
Induction Motor Starters with
DC Injection Braking 2
Using Power Factor Capacitors 4
Induction Motor Temperature Measurement...... 4
Modification Features 4
Preventative Maintenance 5
Troubleshooting 6
Spare Parts 7
Drawing No. RS7-5thru 125 8
Drawing No. RS7-126 thru 1000 9

GENERAL
Benshaw RS7 Series Solid State Reduced Voltage Starters are used for three-phase squirrel cage,
wound rotor, and synchronous induction motors, The RS7 Starter has an adjustable starting iorque
followed by an adjustable voltage ramp with stopping brake torque and brake time adjustments. The
starting torque and voltage ramp adjustments enable smooth motor acceleration to full speed, providing a
soft start, and allowing for full starting torque if and when required. The stopping brake torque and brake
time adjustments enable smooth motor deceleration to zero speed providing controlled stopping times. This
adjustment procedure reduces hazards associated with coasting machinery, overhauling loads, etc.
In cases where load and motor conditions cause instability near the end of the acceleration ramp, an
accel kicks circuit can be adjusted to provide a quick step-up to full motor voltage. The point at which the
step-up occurs can be adjusted from 50% to 100% of the accel ramp.
The RS7 Starter contains seven SCRs--six in a full-wave power circuit, and one as a gated free
wheeling diode. The power circuit is designed to provide maximum torque per ampere to eliminate the
potentially damaging DC voltage produced by a three SCR/three diode starter.
Benshaw RS7 Starters are constructed to permit rapid repair and replacement if required; ensuring
minimum downtime in the unlikely event a failure should occur.
DC INJECTION BRAKING SPECIFiCATION
•Starter Type: AC voltage controlled acceleration
DC voltage controlled braking
“Adjustments: Starting torque: 0% to 100% rated motor torque
Ramp time to full motor voltage: 0.5 seconds to 60 seconds
Accel kick: 50% to 100% of rated motor voltage
Jog at set speed: 0% to 100% rated input voltage
Variable Torque: 0% to 100% rated motor torque.
Brake torque: 0% to 50% rated motor torque
Brake time: L5 seconds to 30 seconds
“Control: Start/stop: Two or three wire--either internal 24VDC (dry contact) or external
12OVAC control power
Jog at Set Speed Control: Momentary jog pushbutton with one (1) set N/C, N/C,
form C contacts either internal 24VDC or external 12OVAC control power
Auxiliary Contact Available: Up to four (4) sets, N/C, N/C, form C jog contacts. (but
no more than a total of 4 sets for form contacts)
PRE-STARTIJP INSPECTION
Ciean out a metalic particles and foreign matter.
2. Check all connections for tightness. Use recommended procedure for aluminum conductors.
3. On high resistance ohmmeter scale, check Li to Ti, T2, T3. Repeat for L2, L3 Check all terminals to
ground. All readings should be several megohms or more.

POWER ASSEMBLY TECHNICAL DATA
Each RS7 Starter contains SCRs which have a minimum peak inverse voltage (PIV) rating of two and
one-half times the line-to-line AC voltage and a root mean square (RMS) current rating normally selected
to be three times full load continuous current of the motor,
RS7 Starters are rated to operate at a maximum continuous Line current (based on HP and voltage> with
a maximum ambient temperature of 40°C at an altitude of 6,500 feet (2000 meters) above sea level,
Derating of one and one-half percent per degree above 40°C and one percent for every 325 feet (100
meters) must be considered when applying RS7 Starters.
CONNECTION PROCEDURES FOR
SQUIRREL CAGE INDUCTION MOTORS WITH
DC INJECTION BRAKING
WARNING!
Equipment is at fine voltage when AC power is connected. Pressing “STOP” pushbutton does not
remove AC mains potentiaL All phases must be disconnected before it is safe to touch motor
terminals or control equipment parts.
REMOVE AC POWER
1. Connect the three-phase AC supply of the correct voltage and frequency to the input terminals Li, L2,
and L3. (Reference Drawing Nos. RS7-5 thru 125 and RS7-126 thru 1000 for connection procedures 1
thru 5.) Wire should be sized according to the motor current. Wire sizing may be determined by
consulting local and/or NEC recommendations.
2a).Connect motor leads to output terminals Ti, T2, and T3.
2b).Referencing the BIPCDCIB1 option card, install Link 6 and remove Link 2 and 5 for brake after run or
jog. Install Link 5 and remove Links 2 and 6 if brake after jog only is desired.
3. Connect a normally open (N/O) momentary start pushbutton to terminals six (6) and seven (7).
‘For two-wire control, connect a N/O contact between terminals five (5) and seven (7).
4. Connect a normally closed (N/C) momentary stop pushbutton to terminals five (5) and six (6).
5. Connect all N/C trip functions in series with terminals seven (7) and eight (8).
‘If an in-line electromechanical starter or contactor is being used ahead of the RS7 Starter, an
auxiliary N/Q contact should be connected to terminals five (5 and eight (8) n place of the
start, stop pushbuttons and top functions, Ensure that al trp fnctons are “ ses w
ce ‘r ie no ai sea icr r cor aceor seop pusnbutt r y
A’) RS’ Starters are supped with motor overload prctecflon Check actor arrepla’e hi)
amperes (FLA) and verify that the supplied overload s properly selected
7 The DC current through the motor must be measured to properly adjust ts level Install a DC immeter
‘n the Starter’s T3 lead to the motor wib the +“ side tcwads thn Rhirtn’ Tb fl( amr+
pLh- Df Qir- at east 3uC’ ‘ the rn”t r, FL ra’

8. On the BIPCRS6AK firing card, turn potentiometers, “RAMP,” fully (clockwise) CW; “STARTING
TORQUE,” fully (counterclockwise) CCW; and “ACCEL KICK,” fully CW. (Reference Figure 1.)
NOTE: Potentiometers are located at the lower left-hand corner on the BIPCRS6AK firing card.
9. On the DC Injection Braking modification card, turn potentiometers, “BRK TORQUE,” fully CCW, and
“BRK TIME,” fully CCW. (Reference Figure 2.)
NOTE: Potentiometers are located at the lower left-hand side on the DC Injection Braking modification
card.
MI MAX 07 1007 LOW
SEC DS
()SEcDt’4ns
HIGH 0, 50/ SEiDS
RAMP STARTING TORQUE ACCEL kICk BRAkE BRAKE
TORQUE TIME
Flgur. 1 FIgure 2
1 0. Apply the AC three-phase power feeding the RS7 Starter.
()SE)S
11. Observe that the “POWER +15” and the “PHASE CORRECT” LEDs on the BIPCRSSAK firing card are on.
(Reference the Troubleshooting Section of this instruction book if steps 1 0 thru 19 do not conform as
outlined.>
12. Press the start pushbutton and confirm that the “RUN” LED on the DC Injection Braking modification
card and the “RELAY ON” LED on the BIPCRS6AK firing card are on. immediately begin to turn the
potentiometer, “STARTING TORQUE,” on the BIPCRS6AK firing card, CW, until the motor just begins to
rotate. Press the stop pushbutton. Repeat this procedure to ensure that the motor turns slowly when
the start pushbutton is pressed.
13, Press the start pushbutton and observe the acceleration of the motor to full speed. All six gate LEDs on
the BIPCRS6AK firing card should be on. To reduce the acceleration time, turn the potentiometer,
“RAMP,” on the BIPCRS6AK firing card, CCW. Repeat this process until the motor accelerates in the
desired amount of time, turning potentiometer, “RAMP,” CCW for a shorter ramp time and CW for a
longer ramp time.
14, If the motor surges near the end of the accel ramp, press the stop pushbutton. Restart the motor and
as soon as the motor begins to surge, turn the “ACCEL KICK” potentiometer, CCW, until the surging
subsides. Repeat this process until the motor surge is minimized.
15. Press the stop pushbutton. On the BIPCRS6AK firing card, the “RELAY ON” LED should turn off. On
the DC Injection Braking modification card, the “RUN” LED should turn off and the “BRK ON” LED should
come on. The “BRK ON” LED should turn off about 1.5 seconds after the stop pushbutton was
depressed.
1$ Calm late the maximum recommended braking current by the following formula:
Maximum Braking Current (DC) = 3 x Motor FLA (AC)
7. On the DC Injection Braking modification card, turn the “BRK TIME” potentiometer fully CW, start the
motor and allow it to come up-to-speed. Depress the stop pushbutton. The “BRK ON LED should turn
on. Gradually :urn the BRK TORQUE polenliometer. UW. until the DC ammeter indicates the des red -
maximum- recommended braking current.

1 8. Check the time required for the motor to stop. If the motor stops too quickly, the “BRK TORQUE”
potentiometer can be turned CCW for the desired stopping time (this will vary for each application and
will have to be adjusted accordingly). DO NOT, in any case, exceed the maximum recommended braking
current. (Reference No. 16., above.>
1 9. The “BRK TIMER potentiometer should be adjusted so that the “BRK ON” LED goes out just after the
motor stops. Repeat the process. starting/stopping the unit until the “BRK ON” LED goes out just after
the motor stops turning; adjusting potentiometer, “BRK TIME,” CCW for a shorter brake time, and CW
for a longer brake time.
WARNING!
Equipment is at line voltage when AC power is connected. Pressing “STOP” pushbutton does not
remove AC mains potentiaL All phases must be disconnected before it is safe to touch motor
terminals or control equipment parts.
REMOVE AC POWER
USING POWER FACTOR CAPACITORS
Power factor correction capacitors can be used in conjunction with the RS7 Starter; however, the
capacitors must be added ahead of the starter and never between starter and motor. If the capacitors are
installed between the motor and the starter, serious damage to the starter and/or the motor may result.
INDUCTION MOTOR TEMPERATURE MEASUREMENT
The motor’s stator winding temperature rise can be determined by recording the winding resistance at
room temperature before operation and after the motor has reached running temperature at full load. Using
a digital ohmmeter capable of reading milliohms, calculate the stator winding temperature rise by using the
following formula:
Temperature Rise: T=(RF/R>-1) (234.5 + t) (Degrees C)
RF=Resistance in ohms of final temperature measurement
R=Resistance at beginning of test
t=Room temperature at beginning of test
MODIFICATION FEATURES
The RS7 Starter may be ordered with the BIPCRS6AK firing card and the BIPCDCIB1 modification card
configured for the following modifications:
PCRS6AKFTrjnGr
AUXILIARY Nb, N/C (FORM C) CONTACTS With this modification, the Form C contacts are supplied to
pick up either at the beginning of the start sequence or at the end of the voltage ramp, Contacts will drop
out when the RS7 Starter is deenergized. (Reference Drawing Nos, RS7-5 thru 125 and RS7.126 thru
1000.>
EXTERNAL POTENTIOMETER VOLTAGE CONTROL This modification supplies provisions to vary output
voitae by an external potentiometer. (Reference Drawing Nos. RS75 thru 125 and RS7•.126 thru 1000.)
4

“BJPCDCIB1 Modification Card
INTERNAL 24VDC (DRY CONTACT) or EXTERNAL 12OVAC CONTROL POWER
“Start/Stop with Auxiliary Contacts
“Hand-Off-Auto
“Start/Stop with Hand-Off-Auto
“Jog at Set Speed
“Jog at Set Speed with Start/Stop
“Variable Voltage
The jog at set speed or vanable voltage options can be operated in two modes. The first mode allows
the starter to apply output voltage instantly up to the selected jog speed or variable setting on the
potentiometer. This is accomplished by adjusting potentiometer, “STARTING TORQUE,” fully clockwise
(CW) and potentiometer, “RAMP” fully counterclockwise (CCW). Both potentiometers are located on the
BIPCRS6AK firing card. Install Links 1 and 3, remove Links 4,7,8, and 9 located on the BIPCDCIB1 card. A
second set of form C jog auxiliary contacts are available, on terminals sixteen (16), seventeen (17),and
eighteen (18) when in this mode of operation,
The second mode allows the starter to apply initial output voltage based on a voltage ramp up to the
selected jog speed or variable voltage setting on the potentiometer. This is accomplished by adjusting
potentiometers, “STARTING TORQUE” and “RAMP”, as per the startup procedures in the RS Series Starter
Instruction Manual for normal starting. Install Links 3,7,8, and 9 and remove Links 1 and 4 located on the
BIPCDCIB1 card. The second set of form C contacts are not available in this mode of operation.
During the initial setup for the desired mode of operation, the potentiometer, “JOG SPEED,” on the
BIPCDCIB1 option card should be adjusted fully CCW. If the variable voltage method is being used, the
variable voltage potentiometer should be adjusted fully CCW. After the initial setup, the jog speed is set by
giving the starter a jog command and adjusting the “JOG SPEED” potentiometer CW until the desired voltage
output is reached. Variable voltage is obtained by giving the starter a run command and using an external
potentiometer to vary the voltage desired.
The second pair of form C run auxiliary contacts are available by installing Link 4 and removing Links
1 ,3,7,8, and 9 on the BIPCDCIB1 card. (Relay K5 must be present on the BIPCDCIB1 card)
Other modifications are available using additional printed circuit cards. Benshaw’s Supplemental
Instruction manuals document the additional modification features.
*nshaws RS7 Supplemental Instruction manual documents the BIPCDCIB1 modifications.
PREVENTATIVE MAINTENANCE
The components of the RS7 Starter will not deteriorate with use; however, some routine inspection and
maintenance is suggested. Periodically disconnect starter input power and vacuum or blow off accumulated
debris on Ihe nternai parts with a high-velocity, owpressure blower.
Power connectmns on newly installed starters may relax and loosen after two or three weeks of
operation. Turn power off and retighten, Check annually thereafter; more often if vibration is present.
Loose power connections can cause voltage spikes, overheating, malfunctioning, or failure.

TROUBLESHOOTING
PROBLEM POSSIBLE CAUSES AREA OF CORRECTION
“POWER ±15 LED 1) AC line voltage not present 1) Check voltage at Li. L2 and L3 lugs for proper
Not On or of improper voltage, voltage.
2) Synchronizing transformer 2) Check voltage at Hi, H2, and H3 of synchro
fusing failure. nizing transformer for proper voltage.
3) Synchronizing transformer 3) Ensure on BIPCRS6AK firing card that X-i goes
secondary wired incorrectly. to terminal I; X-2 to terminal 2; X-3 to
terminal 3; and X-O to terminal 4.
4) Defective synchronizing 4) Measure for 18VAC from X-O to X-i, X-2, X-3.
transformer.
1) Rotate incoming Li and L3 phases.
“PHASE CORRECT”
LED Not On
1)
2)
Incorrect phase sequence.
One phase missing.
2) Check voltage at
voltage.
Li, L2, L3 lugs for proper
3) Low AC line voltage or wrong 3) Verify AC line voltage and synchronizing
synchrornzing transformer, transformer are correct.
“RELAY-ON LED 1) Protective devices tripped. 1) Disconnect power and check continuity with
Does Not Turn On ohmmeter between terminals 7 and 8.
2) Continuity between terminals 2) Disconnect power and check continuity with
5 and 8 not present. ohmmeter between terminals 5 and 8 with
start pushbutton pressed.
3) Start/stop circuit incorrect. 3) Check all trip functions.
Motor Does Not Turn 1) Six SCR LEDs not lit. 1) Change BIPCRS6AK firing card.
2) Six SCR LEDs lit. 2) Defective SCR.
Overload Tripping i) Heater element too small, or 1) Check heater size or adjust overload for cor
overload adjusted incorrectly. rect setting.
2) Acceleration time too long or 2) Decrease ramp time.
high inertia load.
3) Incorrect motor sizing. 3) Verify RS7 HP rating to motor.
Heatsink 1) Fans not operating. 1) Check for proper fan operation.
Overtemperature
Trips
2) Air flow blockage. 2) Clear area.
3) Too high motor HP being used. 3) Verify RS7 HP rating to motor being used.
4 Voltage andicr current exceeds 4 Designed for I I SVAC .5 ama make, I amp
roted 5-: iu-c Of carry and break currant
5) Defective Repiace
Brake torque control 1) 07 & K7 are not connected to i) Verify connection of SCR 7
has no effect 5CR 7
(“BRK ON” LED is lit; 2) Link 2 closed 2) Open Link 2

SPARE PARTS
PART NUMBER DESCRIPTION USED ON QUANTITY
BIPCRS6AK Firing Card AW 1
BIPCDCIB1 DC Injection Brake Card All 1
B1F2809 Fuse Block RS7126 thru RS710004 1
BBF1 Fuses RS7-126 thru RS7-1000-4
BBF2 Fuses RS7-126 thru RS7-1000-4 2
BAF2 Fuses RS7-126 thru RS7-1000-4 1
BlOT Overtemperature Switch RS7-126 thru RS7-i000-4 3
BIF11O Fans RS7-126 thru RS7-10004 3
BICT3005 CTs RS7-126 thru RS7200-4 3
BICT6005 CTs RS7-201 thru RS7-400-4 3
B1CT7505 CT’s RS7-401 thru RS7-600-4 3
BICTI5005 CTs RS7-601 thru RS7-10004 3
BIDVDT-3L DVDT RS7-5 thru RS7-125-4
BIDVDT-1L DVDT RS7-5 thru RS7-125-4 1
BIDVDT-1L DVDT RS7-126 thru RS7-1000-4 4
BISCR5O12X SCRs RS7-5 thru RS7-20-4 4
BISCR7O12X SCR’s RS7-21 thru RS7-30-4 4
BISCR10012X SCRs RS7-404 4
BISCR13212X SCRs RS7-50-4 4
BISCR16112X SCRs RS7-60-4 4
BJSCR21O12X SCRs RS7-75 thru RS7-100-4 4
BISCR25O12X SCRs RS7-125-4 4
B1SCR6601218 SCRs RS7-126 thru RS7-200-4 7
BISCR88O1 230 SCR’s RS7-250-4
BISCRI5001S5O SCR’s RS7251 thru RS7JOO-4
B1SCR220012100 SCR’s RS7-701 thru RS7-1000-4
B1T2081820 Sync Transformer 208V See Voltage 1
B1T2301820 Sync Transformer 230V See Voltage 1
B1T3801820 Sync Transformer 380V See Voltage 1
B1T4801820 Sync Transformer 480V See Voltage 1
B1T5751820 Sync Transformer 575V See Voltage 1
on HP @ 480V
**4 = 480V
For other voltages calculate as follows: —4Q———— x Motor HP = Starter size (rated at 480V)
Operasng voltage
QL
HP @ 208V, take HP x 2.7 FLA FLA divided by 1.2 HP 480V
12 ‘ 23 1 tke rtP — x 24 FIA r d ‘Pij Lv 1 2 t-4P 1
22_FLa F
A’
1

AZ
—- - ———-‘
AC UOTt
L -_-±-i
NOIE&
aJS1*4ER 1EALS
cm
KEEP LOW TACE C(IROL
OLA1 FR 44 PO
INPUIS AJC WOTOR LEADS.
17 18 19 20 21 22 23 24 25 26
3 4 5 6 7 8 9 10 U 2 3 14 15 16
I 1 I I I I I
I I 1 1 I I I I I I I I
SIGNATURES DATE TtTLEi
B ENSHAW
RS7 SERIES 1659ESUflEPRD RftrB0X47.
GLENS4*W i5i CON1N1VO
DRWN 3 -I-8? soup STATE STARTER
CHKD. SHEET 1 OF DWG. No.
GENERAL WIRING DIAGRAN
R57—5 THRU 125
APP.

A, _ J,7 1
RS7—126 TI-IRU 1000
CHKD, — — SKEET I OF I DWG No
— GENERAL WIRING DIAGRAI4 a
DRWN SOLID STATE STARTER
— — — RS7 SERIES SUTT lD R.FL Il SOX 4
GLENXHAWX,
B ENSHAW
SIGNATURES DATE TITLE’
I I I I I I I I I I I I I I I I
e 3 4 5 6 7 8 9 10 11 12 13 14 3.5 16 17 18 19 20 21 a
23 24 25 26
1
I.rT3 C
AflDI •ø4 PO
- i_I
a*i
No
rii
+24C
IMJRY ACTi I
flIAi] 21+
10 U.TA c
1M CA
,
lou +8]
2
iOS7
zs
L
i 17 18 IS
FANS
I ii ii I
Lxi
l3 14
‘•\_- AC UO1O
Ti
•3A
cii
T
-41---—--
I I
I RIj
TIA
—
J.L1
—1