Sencore PR 57 User Manual

PR 5 7

AC “PO WER ITE ” *

Variable Isolation Transformer

& Safety Analyzer

Operation, Application, and

Maintenance Manual

S E N O O B E

AC “ P O W ERITE”

VAMABUE ISO LATION T RAN SFORMER A SA FETY ANALYZER

0 -3 AMPS CONTIN UO US 3 - 4 AMPS INTERMITTENT USE

LINE OUT P UT 17 S W 470 W HI SIDE LO SlOE

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SENCORE

3200 Senc o re Drive , Sioux Falls , S o u th D a kota 5 7107

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WARNING

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Please Observe Thes e Safety Precautio ns

Th ere is alw a ys a danger p resent wh e n te sti ng elec t ronic equip
m e nt. Unex p ecte d high voltages can be pres ent at unusua l
lo c a t ions in d efect i v e equ i pme nt. B e c o m e f ami l i ar with t he equ i p
m ent you’re w o r k i n g with and o b serve t he fo l lo wing sa fety pre 
ca u t i ons.

Every p r ecau t i on has be e n t aken in t he de sign of y our i nstrument to
insure tha t i t is as safe a s p o s s i b le. H o wever , saf e o peration depe nds
on you, t he o p e r a t o r .

1. Ne v er excee d the limits o f this in str ument as giv e n in t he spe c i f i c a 
tio n s ec t io n a n d th e ad diti ona l s p ec i a l war nings in t his ma n ual.

2. N e v e r u se t he PR57 to isola t e yo ur test eq uip ment, o n l y use it t o
isol a te t he eq uip men t that y o u are s e r v i c i n g .

3. N e v e r p l ug mo r e th an one unit at a time into th e PR57. To do so
could defeat t he isolat i o n t ransf ormer and p resent a p ossible sho c k
hazard t o the t e c hnici a n.

4. Remove t h e circu it powe r befor e making conne ct io n s t o hi g h vo lt a g e
poi n ts .

5. D i s c h a r g e f ilter capa citors be f o r e conn ecting test l e a d s to th e m.

6. Be sur e you r e qui pm ent is in go o d o rder. Bro ken o r f r a yed te st l e ad s

can be extremel y da n ge r ou s an d can expose you to dange ro u s voltages.

7. R e m o ve t he te st l e ads i mm e diat ely aft er t he test has be e n com

pl e t ed to reduce the poss i bili t y of shock.

8. Do not wo r k a lone w h e n w o r king on hazar dous c i r c uits. Always

ha v e an oth er pe r s on clo s e b y in cas e of an a c c i dent . Reme mber , e v en
a mi n o r sh ock ca n be the c aus e of a mo re seri o us ac c i dent , su ch as
fall in g ag ain st the equ i pm e nt, or c oming in contact w i th hig h
vol t a g e s .

9. Impr ope r Fuse(s ) Vo id Wa rranty. Fuses ar e for y our pr o t ection, so

alw ays re p l a c e f u s e wi th p r ope r t yp e and current ra t ing. The p r oper
fuse typ e d escript i on i s mar ked near t he fus e holde r and in the
instruc t ion man u al. Alway s :
a. Hav e the proper size re pla cement f u s e in s t o ck. W i t h each new

instrume nt, be su r e to up date y our fus e i nve nto r y w i t h an y
spec ia l v a l u e fus e s your ins t ru ment m ay req u i r e .

b. Av o i d s i tuati ons tha t will blow the f u s e . Whe n a p r otectio n f u se

blows, n ote what cau sed the fus e fai lu re . P reven t futu r e fus e
fai l u r e s b y follo w in g p r oper mea sur i ng procedure s .

PR57

AC “ PO WER ITE”

Variable Isolation Transformer

& Safety Analyzer

Operation, Application, and

Maintenance Manual

VCQ». «*

SENCORE

...the electronic instrument “analyzer people"

3200 SE NC ORE DRIVE, SIOUX FA LL S . SOUTH DAKOTA 57107 -(605 )3 3 9 -0100

1

TA B LE OF CONTENTS

SIMPLIFIED OPERATION

To Read V ol ta ge of AC Line or Isotated O u t p u t

To R ead W a t ta g e or C u rr ent ....................................................................

To R ead L e ak a ge ...........................................................................................

DESCRIPTION

In t r od u cti on .................................................................................................... 6

F eature s.......................................................................................................... 6

Spe c i fi c a t i o n s............................................................................................... 7

Sup pl ied Ac c esso ri e s

Co n tr ol s............................................................................................................10

OPERATION

In t r o d u cti o n ....................................................................................................12

Power C o nn ec t i on .......................................................................................12

Mag ne ti c Cir cu it Br ea ke r/P ow er Swi tch O pe r ati on

Fuse Replacem en t .......................................................................................13

Leakag e Te st Pro be M ou n t in g Cl i p

Using the Var iab le V o lt ag e O u tp ut Fun cti on

Using th e A C Line Mon it o r Po sition.....................................................14

Using the PR5 7 C ur re nt Funct i o n

Using the PR5 7 W a tt s Fu nc t i on..............................................................15

Det erm in in g th e W a t t a g e R atin g of a Unit ...........................................16

Perfo rm ing the Le aka ge T e s t

Dete rm in ing the A llo w ab le Le ak age L evel .........................................18

Testi ng L eak age on Th ree -W ir e Uni t s ................................................... 18

Che ck in g the C al ibr ati on of t he Leaka ge T est

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MMMMi

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APPLICA TIONS

Tro u bl es h oo ti ng Pow e r S u p p l i e s ............................................................20

Troublesho oting Co nstant V oltage Transform er Po wer Su ppl ie s . . 20

Ch eck in g C ir cuit Rep airs at r edu ce d I npu t A C V o lt ages

Refo rmin g Power Sup ply E lec tro ly tic Fil t ers
Ch eck in g the W irin g of the A C Line Cord and P ow e r S wi t c h
Tes tin g T ra n sf or m er Op e ra te d De v ic es for AC Le a k ag e

Read ing AC Le aka ge Le vels Be lo w 100 Mic r oa mp s

MAINT ENAN CE

Dis as s em b ly I ns t r uc t i on s

PR57 Cal ibr atio n Pr oc ed ur e.................................................................... 24

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SERVICE AND WARRANTY Inside Back Cover

NOTES

SIMPLIFIED OPERATION

TO READ VOLTAGE OF AC LINE

OR ISOLATED OUTPUT

m o n i to r AC m o n i to r AC to " ON " to be tes ted
line v o lt a g e vo lt a g e f rom

isol at ed

ou tp u t

TO READ WATTAGE OR CURREN T

6

. Read wa t t a g e or

4 .

Ad ju s t to r
117V on

teste d

TO READ LEAKAGE

12. Depress if a ny
lea k a g e s hows
on mete r

7. and 10. Mak e
conta c t with
exp o se d m eta l
parts

5

DES CRIPT ION

INTRODUCTION

M a ny e l e c t ro nic devic e s t hat op erat e f r o m the AC line d o n ot hav e an
isolati o n tr ans f ormer . So m e o f these ch a ssis have o n e side of t he AC
line connec t ed directl y to the ch a s sis. O t h er devic e s u s e a full-wav e
br i dge rectifie r connecte d to t he ch assis which plac e s the ch a ssis at
one- h a lf th e line vo ltage no matter how t he line co rd is con nect e d to t he
AC line. Th ese chassis must b e isolated fr o m the c omm on sid e of the
AC l ine with a n iso l atio n tr ansfo rm er t o p r event sh ock hazards an d to
prevent t he p oss i bili t y of d am agi ng t he d ev ic e und er te st or t es t
eq uip ment c onne c t ed di r ectl y to the c h a s s i s .

M any new circ u i t tr ouble shoot ing pro c edu r es r e quir e t hat the AC line
vo ltag e be adju stable t o t est regul ators, s h ut-d o wn circuits, a n d o t her
volta ge sen s i t i ve cir cuits. Inc rea sin g or re duc i n g th e lin e v olta ge can
also help loca t e intermi tten t p rob l e ms that do not show up with 117
volts appl i e d t o t he i nput .

Th e abi l i ty to mo nitor t he cu rre nt or po wer d rawn from th e AC line
of t e n si mplifie s trou ble shoot i ng of p o w e r supp l y or p o wer o utpu t
stage pr oble ms. A bno r mal l y hig h pow e r c ons umption in dicates a
pr oble m t hat may not b e i mm e diat ely r e c o g n i z e d bu t wh ic h may c ause
prob l e ms in the f utur e .

Fin ally, every un i t se r v i c e d s h ould be check e d to make sur e that
ex posed me t al p arts do not pose a shoc k h aza r d to the u s e r . A sa f ety
test is r e comme n ded by all manufa ctu r ers . This t es t i s of t en not d o n e
be cause the pr o ced ures g iven in se r v i c e li ter ature a re diffi cult t o per
fo r m an d int erpret .

Th e PR5 7 AC POWE RI TE iM is a n AC s afety s upp l y de sign ed t o ma k e

su r e tha t ev ery f actor re lated t o p o wer is c orrect. The ope r ation is
sim p l if i e d and all of t he fea t ures ne e ded to m e et thes e nee d s ar e includ

ed in a s in g l e , compact i nst rume nt.

FEATURES

Th e Sen c o r e P R57 P OWERITE™ feat ures fo ur f uncti ons in one
compact p a ckag e. Fi r st, the PR57 has a n isolat i o n t ransf orme r t o
isolat e c hassis that hav e o n e s id e c o nnec t e d d i rect l y t o t he AC pow e r
lin e to eli mi nate shoc k hazards dur in g s ervice . T he i so lation
tr ansfo rm er also pr ovides s afe t y for the test equipment and prevents

po s sible da mage to t he set its elf .

Seco nd , t he PR 57 ha s a var iabl e AC tr ansfo rm er that allow s you t o
v ary the isol a t ed A C o ut put volta ge fro m 0 to 140 vol t s AC . You c a n
appl y a hi gh an d low line to ch e c k r egula tor an d shut down circuit
op era t i on or appl y a hig h line to cook out t hat i ntermitt en t tro u b l e .

Th i r d, the PR57 meter l ets you m oni t or the AC line vol t age or the AC
vo ltage f rom t he is ola t ed out pu t . T h e met er a ls o allow s you to mon i t or
th e watta ge and curr ent be i ng d r awn by th e unit un der test. The PR5 7
m ete r let s y o u kno w when the vol t age and po wer a r e r i ght.

F ourth , the PR 5 7 pr o vides a safe ty leaka ge te st so you ca n che c k e a ch
cus t ome r’s s et f or AC line l e a kage as re c omm ende d b y mo st manuf ac

ture rs. T here is no ext ernal re sis tor s or meter s t o hook up with t he
PR 57. S impl y de press a b utton, to uch the exp osed meta l parts with
the S afet y Leakage Test Pro be an d r e ad th e l eakage curr en t on th e
m e t e r .

Th e PR 5 7 PO WER ITE™ a lso fe ature s a mag net i c cir cuit brea ker
ba cked up by a 4 A mp slo-b lo fu se. T h e PR 57 is protected, e v en fro m a
di r e c t s hort on the isolat ed output. Th e PR57 a l s o h as only one iso la te d
o ut pu t t o p r ev ent plug gin g in more tha n on e unit and de fea t ing the
isolat i o n of th e i s olat i on tr ansfo rm er and creat i ng a poten tial shock

ha z ard.

SPECIFICATIONS

ISOLATED OUTPUT:

VOLT AGE: 0-140 VAC (typ ical ) c onti nuo usly v a r ia b l e .

CURRENT: 0-3 Amps conti nuous; 3-4 Amps in termittent usa g e (five

m inute s on, five minutes off).

AC LINE LEA KAGE: 50 uA max., eith er isola t ed outp ut t o gr o und.

AC LINE MONITOR:

LINE V OLTAG E: 0-150 V A C ± 3% F.S. (c alibr ated at 117 VAC).
O UT PU T VOLTAGE: 0-150 VAC, ± 3 % F. S . (ca l i b r ated at 117 VAC).
O UT PU T CURRE NT: Ranges: 0-1.5, 0-4 Amps AC; A ccu r a cy a t an y

o utput voltag e: 3% F.S .

O UT PU T WATTAG E: Rang e s: 0-175, 0-470 wat t s; M e t h od: vo lts

time s am ps p r odu c t; Acc u r a c y : 3% F.S. w ith ou tp ut vol t age se t t o
117 VAC.

SAFETY LEAKAGE TEST (Patent Pending):

R AN GE : 0-800 u A , ± 3% F.S . (calibr ated at 500 uA).
M ETHO D: Re f e r ence d to eit her sid e of is olat ed outpu t jack (switc h

selected).

PROTECTION:

AC INPU T: 4 A mp magnetic c i rcu i t b r eak er b uilt i nto p o w e r switc h.

ISOLATED OU TPUT: 4 Am p type 3AG slo-blo fus e on back pane l.

7

GENERAL:

METER: 4 V2”, mov i ng coil, 1900 ohm , 100 uA F .S . , diod e pr otecte d

aga inst ove rl o ad ; Accu r ac y: ± 2%.
INPUT P OW ER: 105-125 VA C , .4 Amps idle current w i th no ou tput
loa d with 1 17V AC in put.
SI ZE: 6 ” x 11 Vi” x 12W ’ (15.2 x 29.2 x 32.4 cm.) HWD.
WEIG HT : 18 lbs. (8.2 Kg.)

ACCESSORIES (Supplied):

39G 1 4 8 Saf e ty Leakage Prob e wi t h built - in cali brat ion che ck .
64G 3 5 Le a kage Probe Mount i ng Clip
44G 2 3 Sp are 4 A mp t ype 3AG slo-blo fuse.

NOTES

9