W5 Series Variac Autotransformers, Manual


Add to my manuals
6 Pages

advertisement

W5 Series Variac Autotransformers, Manual | Manualzz
,..-..,. INSTRUCfiONS
W5 Adjustable Autotransformer
with DURATRAI(ID contact surface
GENERAL INSTRUCTIONS
1.1 UNE VOLTAGE AND FREQUENCY. The W M:rit:!->
arc designed for u~ ac a minimum frc·
quen<.:yof50 cycle~ per second ( c/!>) for !.he ~rated linevolcage
( 120 v for ~tandard models, 240 V for l)'Pe H models). They
can be operated successfi.tlly at frequencies as high ~ 400 c/~.
but the line-voltage ratings should not be substantially
exceeded. At frequencies abon: 400 c/s, the use ofM series
models is recommended (These models are expr~ly
d~igned for operation at frequencic~ above 350 c/s.) ·me
T)pe H model~ can be operated from a 120-,·olt. 25-cycle line,
but must be connected as for 2-fO·volt, 60 cycle operation.
Current rating.., remain und1anged, but the power rating is
reduced by a fuctor of 2, due to half-voltage operation.
Autotranst(>n11Crs cannot be operated on direct current. Any
attempt to do ll<> will result in a bumcd·out unit.
autotransfom1cr~
and tbe loatl Such devices a... Klixon and Heinemann circ.-uit
breakers are particularly useful where me load is !>ubject to
rugh inru.-.h.
The short-term overload curve, Figure 1, sho~ what your
autotransformer \viU stand under initial surge conditions,
as in motor starting, incandescent lamp Lighting, ctc. At no
tinle should Lhe wut be called upon to furnish a current in
excess of ten times it'i rated current.
1.3 LOADS. Autotransfom1ers arc adaptable to any load dm
lion ofa protectiLY?deL'iceofproper rating between tennina/3
is subject t<> control by voltage v;triation. As a rule, induction
motors cannot thus be smood1ly controlled. However, de
motors (with rectifiers), universal motors (with or without
rectifers), capacitor motors with fun loads, heaters, lights, and
many od1er devices are 5Wtable for such control.
ll1e overvoltagc connection ~hould be avoided where the
load may be damaged by the highcr·than·line voltage available.
When the overvoltage connection i.J) omitted, with a fixed,
known load, maximum currem can be drawn at line voltage.
Since los.o;cs (which vary with brush setting) arc at a minimum
near line ~Uld zero voltages, higher current can be drawn at
these setting.., widlout exceeding normal temperature ratings.
This higher ( maximum) current is of ~-uch value d1at, as me
brush setting is reduced below line \'Oitage, with a constantimpedance load, the current fuJI-off wim decreasing output
voltage keep~ the current \vidlin safe limits. To find the
impedance in ohms of the minimum ohmic load, divide Line
volt.'i by maximum amperes. l11e power rating of this load in
watts is the product of line volts and maximum amperes.
For continuous operation, d1t: rated current of the transformer should not be exceeded. Derate me unit in accordance with
Figure 2 for ambient temperature!'> above 50° C.
Figure 1. Overload limits for tine-voltage connection.
Figure 2. Tem perature derating curve.
1.2 FUSFSANDUNECAPACTIY. Protectrourunitbyplacinga fusing device ofproper rating between terminal3 and !.he
load lhe input line capacity must be adequate for the auto·
transformer, iL., load, additional loads !.hat may be required,
and a margin for slight overload. Bccaust: these transfonncn,
are iron-core dc,ice, using high-performance core material,
normal inrush !'>-urg<.~ up to 10 tinles !.he rated currcm of the
unit may be encountered when it is first connected to !.he Line.
Fuses must be st:lecu:d wi!.h this in mjnd.
Slow-blow ( thermal delay) fuse~ or magnetic or !.hcrmal
time-current integrating breakers arc preferable to the quick·
blow fuse, for d1c input Line and the load circwt.<;. ·rype MT
models are equipped wid1 a them1aJ breaker in the load circuit
to protect the unit from accidental overload This practice
mt~)• u•ise(vbeappliedtootbermodelsbytheuserbytheinser·
100
1000
j"...
''ovERl..OAO LI MIT
900
eoo
\
I
90
........
80
~
....<t~700
cr. 600
1\
'
0
..J
~500
a:
\
0400
r
z
a
4Hc
"'
XI()
tf
200
, j!l(l
I
I
!a HOUR·t)3 ~
1
1'-.i'..
i"'--r--
tOO
I_!;
-
I
I
CUR·t20~
1-1-
I
24 HOUR$-1001.
II
I
2
S
I()
TIME IN MINUTES
1,000
1\.
\
0
1\
\
0
0
01
'\.
0
0
04
""
10,000
•o
lOA
~0
Ill
••o
10
80
t!!e
"'
AMIIENT TEMPUATUIE
120~ ~PR1 ~1ARY
120V PRIMARY
AUf•lTRJl.,S~OFl,.(R4-
_.-
,'7 v
_
_
_
.....__ _ _ _ _ _ _ __.J
6 0V <oSEC0 NDARY
~UPPLEME NTARY
TRANSFOR MER
VOLT-A MPERE RAT NG
SAME AS
AUTOTRANSFORMER
SE .,.ON DAP Y
~~~~-------------
~
I
LINE
120V
•
LI N E
I
M AXI M U r J ;RR E N T •
17 '
120V
LO AD
60-1 20V
M AXI MUM CU RRE NT •
2 • RA TED CURREN T
RATED cu RRENT
I '---------------·--------
SUPPLE ME N TAP Y
TRA N S• ORMER
VOLT- AM PER E RAT N G SA ME AS
AUTOTRANSFORMER
AUTOTRANSFORMER
Figure 3. Supple me ntary low-voltage trans·
former usefi•l for applicatio ns sud 1 as control of
vacuum-tube heaters.
Figure 4. Supplem en tary 2:1 transfonne r useful
for applications sudl as control of resistance
furnaces.
When a load require~ regulation over a Limited range on I}'. a
~upplemcntary, fixed, Mtp·down tr.tn~former give. more ~mb·
f.tcrory and economical operation. l11b pr.lctice re~ult.~ in:
a. an incrcaM: in current rating in the ratio of line vollagc
operating range.
b. finer adjustment. since the operating range is spread out
O\'Cr the entire winding.
c. longer unjt life. a~ the bru~h tra\'Cr-.c~ the entire winding
rather than a limited arc.
T)picaJ cx:unple~ arc illu:-.trated in Fihrurcs -~ and ...
1.4 SWITCHING l b avoid dangerous surges. aJways set the
pointer to zero before switdling in the load circuit.
1.5 MAINTENANCE.
WARNING
AJways di!.connect the autotran~tbrmer from botb :,i<.k.~
of the Line before anempting any maintenance work.
load, although the presence of an abrasive dust c-.tn accelerate
wear ofboth brush and bru~h track. Brush e<tem.ion is limited
to prevent contact between the metal brush shell and the
winding. Operation of th e brush beyond its extension limit
results in <trcing, indicated by a voltage drop under load.
Replace bn1she!> before thjs limit is reached.
Type WS models use the Techrupower Type VB2 brush
assembl)~ Tn>e W5H m<xleb. the Tnx: VBl ~cmbly. To
replace either <L'>....ernhly, rotate the top plate to clear the retaining pim.. Proper brush inM:rtion is indicated by a click, or
detent action, (C) the long :oo~ of the top plate is aligned with
the retaini ng pins. Newly installed or reinstalled brushes must
be correctly seated for proper operation. With power off, a
few S'iving!> of the brush over the abr:lSive side of a piece of
crucll!> cloth resting on the bm~h track will effectively mate
brush and tr:tck. RemO\'C the crocu~ cloth and blow or brush
loose carbon from the bru~h track before appl)ing power.
1.6 SERVICE.
1.5.1 BRUSH TRACK. l11e brush track it. stabilized by the
Duratrak contact !>urface. lf cleaning becomes necessary u~e
onJy a soft cloth and a safe SOI\'cnt ~uch a.!> alcohol or "white"
(non-leaded) g<t.,oline. Do not liM: abr:t.,ives; their action may
d(.~troy the stabilized ~urface.
If , for any reason, you feel that your urut does
not operate properly, write lO our Service Department, giving
operating details, circuit diagr:lrn, input and olltput vol tages
and current~.an<.l load t)pe and r:tting.
\X'hen returning a urut for rcpajr. or for any other reason,
please write to our Senice Depanmem first, reque!>ting shipping instruction..,. State the t}pc number and the date of
purcha.'>C. Pack tJ1e unit carefully. Renm1ed uni~ often ~11ffer
more damage in shipment d1an in M:rvice.
bru~hes will last indefinitely.
Rapid brush wear is an almost certain sign of over·
1.5.2 BRUSHES. Normally,
SPECIFICATIONS
INPUT
-
Type N o.
Vol h
OUTPUT
<I s
Vo lts
Ra ted
Amps
Max
Amps
Ma x
KVA
W5
120
50-60
0 - 120
0-140
6.
6.
7 .8
6.
0 .94
W5M
120
50-60
0-120
0-140
5.
5.
6 .5
0.78
0-120
0·140
5.
5.
6.
2.6
2.
W5MT
W5MT3
}
120
W 5H
)
W5HM
W 5HMT
l
1
50·60
{
5.
5.
-
0~2}
240
240
120
120
120
50-60
50-60
50-60
25
25
0-240
0-280
0-280
0-120
0·140
2.
2.
I.
2.
2.
2.6
2.
0.31
240
240
120
120
120
50-60
50-60
50-60
25
25
0-240
0-280
0-280
0-120
0-140
2.
2.
J..
2.
2.
2.4
2.
I.
2.4
2.
0 .58
I.
60-crtl•
N o-load
Wotts
Ounce -Inch
Dri ving
Torq ue
9
10-20
9
10-20
9
10-20
Net Weigh!
Pou nds
6l~
13.1 kg)
7 1h
(3.4 kgl
8 'I~
(3.7 kg)
0 .63
-
-
6 1h
9
10-20
7%
(3.3 kg)
-
--
0.29
-
13.0 kg)
9
10-20
8
(3.6 kg)
Surface
Mounting
I
I
I
I
!TERMINALS
6 AND 7
PRESENT ON
H MODELS
ONLY)
Ws
{
WSH {
Back-ofPanel
Mounting
I
I
I
66
0:
L_________
7 J'
a
LI NE : UO •olh, SO to 60
LOADt 0.140 fOih
I
b
•It
LINE : 140 •olll, SO t o 60 eft
LOAD : o. Jio
••It•
Ws
6
{
WSH {
d
LINE : 240 • olu, SO to 60
LOAD: 0.140 volh
6
6
WSH
6 _ ___ ___
7 JI
L__
I
LI NE: 120 ulh, SO t o 60 • / •
{ LOAD: 0·%10 ..1u
</t
'
I
6 0:
'L ____ _____
I
e
6
1
7 J
I
6/
f
I
o~
I
1
I _____
6
7 JI
L
____
c
I
I
I
_-·
' ,,
1
LINE: 120 •olh, SO to 60 </ •
LOAD: 0·12:0 • olh
'I
I
0
~ 5
I
L_ _~ ____ _!_j
I
1
Surface
Mounting
I
I
J
!TERMINALS
6 AND 7
PRESENT ON
H MODELS
ONLYI
Back-ofPanel
Mounting
_____
_ __7 _ j I
6
•tf ground ia neceuory, co mmon lin e·loo d terminal mual connect to gro und aide o f line.
Figure 5. Recommended line and load connections to the autotransformer.
TYPE W5 and W5H AUTOTRANSFORMER
2.1 GENERAL The bao;ic 1yPe W5 or WSH autotransfonner is
an uncased unit for back-of-panel mounting, with combination
screw and solder-lug terminals p rovided. Figure 6 may be used
a'i a drilling template.
2.2 THREE-HOLE MOUNTING. TI1e drilling template may
be used directly to lay out the three wlit mounting holes, t:hree
dial·plate mounting holes, and the shaft clearance hole. The
mou nting screw heads must be tlush or subtlush with the panel
surfuce to avoid interference with the dial plate.
2.3 FOUR-HOLE MOUNTING. TI1e drilling template may be
used directly tO .lay out the four unit mounting holes, t:hree dialplate mounting holes, and the shaft clearance hole. The four
mounting screws do not require countersinking or counterboring, since there is sufficient clearance for the dial plate. Be ~ure
the base is fiat against the panel. Do not overtighten any of the
mounting screws, as this may distort or tip the base.
2.4 GENERAL
MOUNTING
INFORMATION. Excellent
heat-transfer characteristics e..xist between the coil and base and
between the base and panel. A marked reduction in opemting
temperature can be realized if there is good thennal contact
(tight parallel mounting) between the bao;e and a metal mounting panel ofany substanti'll area. It is recommended that the unit
be installed where adequate ventilation is available, and well
away from hot instruments. ln monnting d1e reversible dial
plate, use the scale that confonno; to the load voltage range of me
selected wiring cormec:tions. To adapt shaft projection for
various panel thicknesses (%'' maximum with standard shaft),
loosen me two setscrews in the mdiator hub, move the shaft as
required, and retighten the setscrews. Longer shafts are avai11ble
at slight extra charge, and should be used on panels thicker than
W'. The shaft should project not less dum 3/ 16" from the
mdiator hub to allow adequate overiru;ulation distance between
hub and shaft core. The pointer should be at zero with full counterclockwise rotation.
2.5 WIRING. Wiring circuits are shown in Figure 5. When
making connections, avoid loose "whiskers" and keep wiring
free from contact wid1 working pans.
1YPE W5M and W5HM AUTOTRANSFORMER
3.1 GENERAL The 1}pe W5M or Type WSHM model is a
cased unit for either surface or back-of-panel mounting wid1 BX
or conduit connections. (See Figure 7.)
3.2 SURFACE MOUNTING. TI1e procedure for surfuce
mounting is as follovvs:
a Remove the slotted screw on top of cover, and the knob.
b. Swing rl1e cover away and down Remove cover.
c. Fasten r.l1e unit to the supporting structure with four
woodscrews, machine screws, or bolts, passing through the
base and case and into or through the support.
d Removeknockoutsasrequiredbystrikingsha.rpblowswith
a hammer and screwdriver on the sides of the knockout where
the metal has been sheared, and twisting the knockout. Do not
strike at d1e small metal ties and do not pry. Wire according to
circuit a, b, or c shown in Figure 5. See directions for dial plate
mounting given wid1 circuit diagram.
e . Oleck wiring for accuracy and for clearance of live pans.
( Replace the cover and knob. Align the pointer so that it L-; at
zero with full countcrclod-v.'isc rotation.
3.3 BACK-QF-PANEL MOUNI1NG. l11e procedure for back·
of-panel mounting is as foiiO\"\"S:
a Remov·e the ~lott<..>d :.crew on top of cover, and the knob.
b. wing the cover away and down. Remove cover.
c. Loosen d1e ~~T<."Wl> in the radiaror hub, and push the shaft
to project through the panel. Maximum panel thickness "id1
standard haft Lo; ~~~ ". Longer shafts are available at slight e.x'tra
cllarge, and should be used on panel-; thicker than %". l11e ~haft
should proje<.1: not les!:> than 3/ 16" from the radiator hub to
allow adequate O\'Crinsulation distance between hub <md
shaft core.
d Remove the dial plate for later mounting on the panel
e. Mount the nan1eplate over the shaft hole, if desired. Holes
are provided for this purpose.
( Drill the panel i n accordance with template direction.-;
(Figure 6). Provide holes for dial mounting and shafi.
clearance.
g. Mount the unit on the rear of the panel.
h. Attach the dial plate to the from of the panel. "iththe M:lftapping M:rl.'Wl> that initially fastened the dial plate. liM: the
\'Oit.'lgc 'l<:alc: appropriate to d1e connections.
i. Anad1 the: knob on the from of d1e panel. Tighten the:
:-.ct...crt:\v~ in the radiator hub. setting pointer at zero ''id1 full
countcrcloch.,,i:-.c rotation.
j. Rl.-n1ove knockout.,~ requir<.>d by!>lrikingsharp blowl> "idl
a han1mcr :md !.<-Tl.''wdriver on the !>ide. of d1e knockout where
the metal h:L., been !Jleared. and twisting the knockout Do not
strike at tJ1c l>maJI metal tics and do not pry. Wire according to
cin:uit d. c. or f, Figure 5.
k Check \\iring for ac<.l.LI"'JC)' and for clearance of lh·e part'>.
I. Replace tJ1c CO\cr.
rn. Autotran.,fbm1er.. ~u-c usually mounted with d1e long axi~
vertical :md tem1inal plate up. lf required for wiring con·
venience or bccatL'><: of space limitations, d1e long ~uds may be
horizomal, or tenninal plate down. In aU cases d1e dial should be
oriented l(>r convenic:nce in reading,
1YPFS WSMT, WSMT3 and WSHMT AUTOTRANSFORMER
4.1 GENERAL lhe t)pe. \X' 5MT and WSHMT models arc::
cased (totally encloM..x l) unit., that include a power cord and
plug. an OFF-QN switch that !.'Witches both sides of the line. an
oudet plug for the connection of the load. a manual reset
overload protector. and a calT}ing handle. Thel}pe MT models
arc:: designed for usc in laboratories, industrial plantS, and other
locations where a portable ac \'Oitage-adjusting de\ice of high
effidency is required
The 1)pe WSOMT3 model has a third circuit in the power cord
and plug and in d1e load outlet lhis circuit is a safet)' feature ro
provide for automatic grounding ofthe uninmd Load enclosures,
to reduce the ha7..ard of shock, should Line-circuit partS acddentally contact the ca.o;e, or frames.
4.2 OPERATION. ·n,c operating procedure is a'! follows:
a Connect the power plug to a Line of proper voltage and frequency, as determi ned from d1e nan1eplare.
b. With d1e ~'Witcl1 OFF ~md d1c: pointc:r set to zero, connect
the load The load should be able to wid1Stand the highest out·
put voltage contemplated, and should at no setting draw more
than the rated current of the rransfbrmer.
c. To apply voltage to the load, rum the switd1 ON and advance
the pointer setting to the desired value. Operation is
®
IET LABS, INC.
rn the
534 Main Street, Westbury, NY 11590
unatfccted by the: pol>ition of d1e transformer.
d. 'l}pc;: MT m(xleb arc normaJJywired for overvoltagc: output
( Fi~:,'llre 5d ). m1d arc supplied equipped with ;m O\'Cf\'Oitage dial
Thq· <-~m be supplied on !>pedal order "'ithline·,ultage output
(Fi~:,rure 5e) :md a dial for thL., connection. at a slight t:.'\.'tra CO!!l.
T)pt: 11,\1'1' modc:L., may be reconnected for 12Q-,·olt input and
280-volt output. a.., :.ho"n in Figure Sf (refer to paragraph e.
below).
c. Overload protection L., prmided by a d1ermal trip
de"icc:, whid1 di-.connect.:. the load under conditions that might
ca~ the safe oper:u.ing temperature to be exceeded The ther·
mal capadt)•iss1.1fficicm to allow model"'.ue short-time O\'Crload.,
that will not h:Ul11 tJ1e unit. After correcting the overl<Y.td condition. reset the tripped connector by pressing d1e red reset button. Make sure tJmt the protector has had time enough to cool.
'I11~.: circuit breakc:r is set according to rated current. and
d1erefore \vi II not fi.mction when a 1)pe WS Hl\1T model is connected:!.,') shown in fif:,'l.Lr<: Sf. since these connections cause a '50percent reduction in rating.
( To g:tin acces.., w moving parts for maintenance, disconnect
me power cord, ~md remove the four slotted scrC"\\'S, and puJJ the
cover out <md off.
GenRad Tradrbon
www.letlabs.com
TEL (516) 334-5959 • (800) 899-8438 • FAX: (516) 334-5988
7.1 mm
*4 HOLES 9/ 32 DIA. DRILL
OR TAPPED 1/ 4·28 AS
PREFERRED TO MOUNT
( HOLE CLEARANCE
FOR 1/ 4 BOLT)
OR
3 HOLES 7/32 DIA. DRILL,
COUNTERSINK FOR NO. 10
FHMS TO MOUNT AUTOTRANSFORMER
\
3mm
3 HOLES .120 DIA. (NO. 31 DRILL)
TO MOUNT DIAL TO PANEL.
I
95mm
'It\!
~
.........- -- -- 3 4~ - 95mm
- - - --...!
11 mm
~7~------ 4 _j_
/6
2
114 mm
* FOR uM" MODELS: 4 HOLES .219 DIA . 5.5 mm
(7/ 32 DRILL) TO MOUNT
(HOLE CLEARANCE
FOR 3/ 16 BOLT)
4.8 mm
Figure 6 . Mounting Template for Types W5 or W5H autotransformer.
114 mm
12.7 mm
1/2 DIA . DRILL FOR
SHAFT CLEARANCE.
167 mm
9.5 mm
~
Max Pane;
143 mm S
e
~31lII!mm
83
mm - - -
,--
' -- f
_J
-•
I
"'
1
o2mm
DIA
4DIAL
t
~3~~
1
1
1
1
1
16
a((f--0::\ --1-.
2
5
.120
- R
~ 31 Dnll
.
"o··
Engravi~g
/VV
I\
I ,
4
~o,
95
o
r
1
1
34
1
'-..._L
0 -
7
124 mm
0
57
9~
2~
4
.K...
3 mm
120°
~
20° 20o
4 mm
"" For Cased Mode l
Panel Drillin 9
For shaft And
Dial Plate
r ~ ~u
/
12oo
4!. ~
3 ~ -.J
65mm
15.9
12.7mm- Qia
11
m
I
I' - - - -
-.1.
*
(~20°f I~ 42 *
- I 0\120~
I==::LJ 4-t
-f-- o
o
'
:f)
---'---~
mm~.!_ _J
100mm
I
9
I
PLATE
I
I,____
l,,l
16
2
11 mm
-
r-'
I JlI
1
I
1
16
I
*
rr~5~--.,.-,..,
6
Figure 7 .
Dimensions of Type W5 or W5H
autotransformer
' Max Engraving

advertisement

Was this manual useful for you? Yes No
Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Related manuals

advertisement