Handling & Storage; Acceptance Tests - GE RPM 13A Instructions Manual

GEH-2()3~
Timing Relays Type RPM
'rhe rmmmum pickup of the rotonoid
i:> '('leU below the pi(~kup level of the "'IX"
relay
or about 50% of rated voltage.
THE
TIMING OPERATION
The maximum operating times of tIlese
RPM :relays are either "one" or "three"
seconds depending upon tile nlOdeI. The
minimum operating time is in
the
order of
0.1
seconds.
The desired operating time is con~
trolled by cams which can be set at any
position on the Ume dial. These cams as
they rotate >.will close the front and back
contacts called TU-1 and TU-2 respectively.
The cams in passing will hold the contacts
closed for a specific time called "DWELL
TIME". Some of tile models have tile front
contact maintaining, cam shaped to hold the
contact closed through the balance of the
time range. The back contact on the con-
tinuously rated relay is in effect maintainild
by a contact of the "TY" r.elay which seals
around'1;'U-2.
NOTE: The "dwell" time will vary depend-
ing upOn the time range and position of the
cam. See Table No.
A
for details.
The cams cannot be set togetller to
operate their contacts at tile same time.
The time difference between the closing of
the front contact and the back contact with
the cams set as close together as the
mechanism will permit will vary depending
on the time range and the position of the
cams on the dial. Fer the one second rel;j.y
this time difference range will be between
0.030 and 0.06 seconds. The range for the
three second relay i~ .08 to 0.12 seconds.
Under nor!llill operating voltage, the
operr4tingtb:pe at the maximum dial setting
will be accura.te within
±.
5%. As the dial
scal.e settings are decreased, the variation
will apprqach a maximum of ::, 10% of. the
scale reading. The consistency of the op-
erating time on any specific setting will
be within
±.
2%.
The resistance of the various relay
: components is shown in Table D.
CONSTRUCTION
The general construction of these re-
lays is shown in Figs. 1 and 2.
The basic elements are the driving
magnet"the gear train, the damping magnet
and the time dial assembly. The auxiliary
elements such as the telephone type relay,
targets and seal-in unit round out the con-
struction.
The driving mag;net, or rotonoid
charges two spiral springs as
it
rotates
approximately 180 degrees. One of the
springs located on the rotOnoid. serves to
l'eset tbe as.sembly. The other in the gear
train drives the gearing and the associated
damping system.
The gail!;' train
~s anacCl!r~t~!y~~I.'1~~­
bled clock type mechilnism mounted be-
v,veen two parallel plates in such a manner
as
to
provi(ie proper shaft .end play and
gear mesh (see Fig. 3) . . The charged
spring drives this mechanism at a speed
which is controlled by the damping system.
A ratchet-pawl assembly permits quick
reset: The damping system consists. of a
copper cup mounted on a shaft rotating in .
an annular gap across which exists a
permanent magnE)t field. While the position
of the cup in the magnetic field will provide
some control
of
the time, the main control
varies with thEl. degree
to
whiCh the spring
is charged. On the one second relays the
length of the copper cup has been repuced
to provide less drag which. helps to obtain
the faster operating time.
The time d'lal assembly is mounted
on the out-put shaft of the gear train. The
un~t consists of adjustable insulated cams
which Operate the TU~l and TU-2 contacts.
There are pointers on the cams which can
be lined-up on the time dial scale. The
time dial scale on the three second relays
is calibrated in tenths of a second. The one
second relay is calibrated in cycles (60
cycle bases) with graduations of 2.5 cycles •.
TABLE
P
VOLTAGE
T
RESISTANCE IN OaMS
RATING
I
TU R1 TX RS
TY R4
250
I
100 300 5000 5000
7500 7500
220
I
100 250 5000 5000 7500
7500
125 100 100
5000
7500
110 100 75 5000 7500 7500
48
I
7
}'3.5
200 200
425 425
32 7
6
200
70
24 7 3
200
425
CURRENT
I
RESISTANCE IN OHMS
RATING
!
TARGET
SEAL-IN UNIT
0.2A
I
7.5
6.0
1.0A 0.35 0.25
6
The relays may have either a pointed
shaped cam in the front position which in
passing closes the TU-1contact momen-
tarily or
a
contact maintaining cam which
when engaging the TU-1 contact holds
it.
closed throughout the timing range.
The "TX" and "TY" components are
telephone type relays.
The seal-in unit is a small hinged
armature type relay consisting of a "U"
shaped magnet frame, fixed pole piece,
armature, and a tapped coil. The arma-
ture carries a "T" shaped moving contact
which bridges the two stationary contacts.
The targets are hinged armature as-
semblies with armatures painted orange.
When operated they release a shield which
drops and exposes the orange colored sur-
face of the armature.
RELAY CASE
Components of each relay are mounted
on a cradle assembly which can be easily
removed from the relay case. The cradle
,is locked in the case by means of latches
at the top and bottom. The electrical con-
nections between the case-block and cradle
block are completed through a removable
cDnnection plug. A separate testing plug
can be inserted in place of the connection
plug to permit testing the relay in its case.
The cover is attached to the front of the
case and includes the target reset mecha.-
nism and an interlock arm to prevent the
cover from being replaced until the con':'
nection plug has been inserted.
The case is suitable for either semi-
flush or surface mounting. on panels up to
two inches thick. Hardware is available
for all panel thickness up to two inches,
but panel thickness must be specified oil the
order to insure that the proper hardwar.e
will be provided. Outline and panel drilling
dimensions are shown in Fig. 14.
RECEIVING, HANDLING AND
STORAGE
These relays, when not included .as
a
part of a control panel, will be shipped in
cartons designed to protect them against
damage. Immediately upon receipt of a
relay, examine it for any damage sustained
in transit. If injury or damage resulting
from rough handling is evident, file a dam-
age claim at once with the transportation
company and promptly notify the nearest
General Electric Apparatus Sales Office.
Reasonable care should be exercised
in unpacking the relay. If the relays are
not to be installed immediately, they should
be stored in their original cartons in a
place that is free from mOisture, dust, and
metallic chips. Foreign matter collected
on the outside of the case may find its way
inside when the cover is removed and
cause trouble in the operation of the relay.
ACCEPTANCE TESTS
Immediately upon receipt O.f the relay
an inspection and acceptance test should be
made to insure that no damage has been
sustained in shipment and that the relay
calibration has not been disturbed.