Emerson CVS Hardwired Constant Voltage Transformers User Manual

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Introduction
This operating and service manual has been prepared to ensure that your
Sola/Hevi-Duty Constant Voltage Transformer can
be operated and serviced with minimal effort and
involvement. This manual covers Sola/Hevi-Duty
Constant Voltage Sinusoidal (CVS) Transformers.
Installation - Mechanical Position
All stock sizes with end housings are intended to be
mounted with the silk-screened this side up legend
facing upwards. This will place the ventilated capacitor
compartment downward, thus providing cooler
operation of the capacitor(s). However, all units will
give satisfactory performance if mounted in a horizontal
position. In either case, the unit should be mounted in
an area where it is unlikely that anyone will come into
contact with the core surface of the unit.
Mounting Considerations
If a unit is to be wall mounted, the mounting hardware should be sized as in
Table 1 below. All mounting holes provided must be used
.
Table 1: Mounting Screw/Bolt Sizing
Figure 1: Mounting Holes and Dimensions
Installation – Electrical
On 60VA or smaller units, screw-type lugs in the outlet box are marked “input”
and “output”, and no connection diagram is necessary. Units rated 120 to
15000 VA are provided with multiple inputs for any one, two, three, or four
different line voltages, and some have provision for three-wire output. With
all units, a connection diagram is attached to the inside lid of the box cover, or
inserted in the outlet box. Figure 2 shows typical connections for –8 models,
and Figure 3 shows multiple input connections for all other models. Figure 4
shows the output connections for all models.
Figure 2: Electrical Connections for -8 models
Input & Output Connections – All except 250 VA
Input Connections - 250 VA Only
*Note: The entire load up to the rated capacity of the unit can be drawn from either half of
the 240 volt winding. It is not necessary to divide or balance the load.
Table 3: Recommended Wire Sizes and Fusing
* Leads in the wiring department must be sleeved with 105
o
C sleeving.
Figure 4. Three Phase Connections
A: Isolated, Single Phase Loads
B: Separate, Single Phase Loads in Grounded Wye
Multiple Operation
Two CVS transformers with the same rating may be connected with their
inputs and outputs in parallel. The regulating action will usually be excellent
although the standard ±1% cannot be guaranteed. Series connection of either
input or output is not recommended.
Use With Rectifier Loads
The ratio of crest to rms values is approximately 1.3 at rated load, and slightly
lower at fractional loads. This factor must be considered when all or a portion
of the voltage is rectified. The rectified voltage will now be 10 – 15% lower
than if connected directly to a sinewave source.
Operation With Motor Loads
Because of the current limiting effect described later, special attention should
be given to motor applications. In general, the CVS must have a load rating
nearly equal to the maximum power drawn during the starting cycle. This may
run from two to eight times the normal running rating of the motor. In doubtful
cases, it is advisable to measure the actual starting current.
Cascade Operation
For applications requiring close regulation, two CVS transformers may
be operated in “cascade”. The output of the combination will show little or
no detectable change arising from supply line variations of up to ±15%.
However, the combined units will still be frequency sensitive (as discussed
under Effect of Frequency, page 15). Since even good power systems may
vary in frequency by 0.1% or more, the output of a Sola/Hevi-Duty cascade
combination may vary by up to 0.25% from this cause alone. In actual
practice, then, a cascade combination is highly recommended for special
applications requiring regulation in the general region of ±0.25%. If the
tandem setup is to be operated at near full rating, then the Type CVS “driver”
unit should be one standard size larger than the driven unit, in order to
overcome the losses in the latter.
Outline A Outline B Outline C
All Except 250 VA250 VA only
Constant Voltage Sinusoidal Transformers
Operating and Service Manual
Figure 3: Electrical Connections for Non-8 models
Note: Secondaries are not grounded. Ground X2 per Code.
Rated VA of Regulator Min. Diameter of Steel Mounting Screw
30-120 #10 Machine Screws
250 1/4” bolts
500 to 1000 5/16” bolts
1500 to 10000 3/8” bolts
15000 1/2” bolts
All ratings depend on natural draft air circulation for cooling. They should not
be mounted in conned or enclosed spaces unless special provisions have
been made for ventilation. Technical Services is available for assistance in
doubtful situations (see note on Operating Temperature). Table 2 and Figure 1
show model number with their weight and physical dimensions
.
Table 2: CVS Weights and Physical Dimensions, 60 Hz Single Phase
VA
Catalog
Number
Outline
Drawing
Dimensions
Approx.
Shipping
Weight (lbs)
A
(in)
B
(in)
C
(in)
D
(in)
E
(in)
F
(in)
G
(in)
H
(in)
30 23-13-030-2 A 6.12 5.19 3.47 4.00 3.50 3.00 1.75 .22 x .59 7
60 23-13-060-2 A 6.94 5.19 3.47 4.00 3.50 3.00 1.75 .22 x .59 9
120 23-22-112-2 A 8.12 5.19 3.47 4.00 3.50 3.00 2.44 .22 x .59 13
250 23-23-125-8 A 10.50 7.56 4.75 5.63 4.75 4.12 3.03 .39 x .69 28
500 23-23-150-8 A 13.00 6.50 8.12 9.00 8.12 5.62 3.06 .38 x .81 37
1000 23-23-210-8 A 17.25 6.81 8.12 9.00 8.12 5.62 5.25 .38 x .81 63
2000 23-23-220-8 B 17.58 9.44 10.56 12.75 11.75 3.88 5.19 .44 x .69 109
3000 23-23-230-8 B 18.96 9.44 10.56 12.75 11.75 5.25 5.19 .44 x .69 142
5000 23-23-250-8 B 28.53 9.44 10.56 12.75 11.75 8.25 8.88 .44 x .69 222
7500 23-28-275-6 C 26.91 9.27 23.55 25.81 24.81 6.62 8.88 .44 x .69 365
Three-Phase Power Wiring
If operation from a three-phase source is required, three hardwired regulators
may be wired in delta as shown in Figure 4.
Other Considerations
It is desirable to have a switch in the input circuitry for turning off power to
the unit when it is not in use. While all CVS transformers are designed for
continuous duty, they draw appreciable current regardless of output loading.
The outputs of all Sola/Hevi-Duty standard CVS transformers are isolated
from the input lines. Voltage generated by internal leakage currents will occur
with respect to ground. This can have undesirable effects in many pieces of
electronic equipment. Therefore, if Figure 4 circuit “B” is used, it is suggested
that the installer remove X2 grounding on –8 units, then connect all X2 from
each phase to one location and ground at that location only. This is not
required for circuit “A”. This will not affect regulation or the ability to reject
power line noise or transients.
Any three stock units having a tap for 190-260 input connections may be
connected in delta to a 240-volt, three-phase power supply. Those units
equipped with primary tap for 175-235 volts may also be connected in delta
to a 208-volt supply. (Terminals to be used are identied on the connection
diagram located on the inside face of the outlet box cover.)
All stock production, harmonic-free units now have uniform terminal polarity.
This eliminates the need for “phasing out” either input or output connections.
Output must serve three, independent, single-phase loads of the same total
volt-ampere rating. Connections should be made in one of two ways shown
in Figure 4.
Use With Switchmode Power Supplies
If a CVS transformer is used as a source for a switchmode power supply, a
slight amount of ringing may be noticed on the sinewave output of the CVS at
half cycle intervals for a short duration. This ringing occurs at the point when
the switchmode power supply current demand drops to zero. The ringing
should not be a cause for concern since it is of relatively low magnitude and
frequency. The CVS has been tested with a variety of switchmode power
supplies and it has been determined that the ringing never affects the D
outputs, nor has it been found to degrade the components of any switchmode
power supply.
Volts Input Jumper Volts Output
95-130 H1-H2
(H1 + H3 + H6 + H8) (H2 + H5 +
H7 + H10)
120
X1 – X2 or
X2 – X3
175-235 H1-H4
(H2 + H3) (H7 + H8) (H1 + H6)
(H4 + H9)
240 X1 – X3
190-260 H1-H5
(H2 + H3) (H7 + H8) (H1 + H6)
(H5 + H10)
380-520 H1-H10 (H2 + H3) (H5 + H6) (H7 + H8)
Volts Input Jumper Volts Output
95-130 H1-H2
(H1 + H3 + H5 + H7)
(H2 + H4 + H6 + H8)
120 X1 – X2
190-260 H1-H4
(H2 + H3) (H6 + H7)
(H1 + H5) (H4 + H8)
380-520 H1-H8
(H2 + H3) (H4 + H5)
(H6 + H7)
Primary Voltage
Interconnect
Connect
Lines To
30 & 60 VA 120 VA 7500 VA
120 N/A N/A
Note: H3 & H4
are not used
H1 & H2
N/A 120 240
H1 to H3
H2 to H4
H1 & H4
N/A 240 480 H2 to H3 H1 & H4
Secondary Voltage
Interconnect
Connect
Lines To
30 & 60 VA 120 VA 7500 VA
120 120 N/A X1 & X2
N/A N/A 120
X1 & X2 or
H3 & X2
N/A N/A 240 X1 & X3
CVS Input Output
VA Rating
Rated
Volts
Req. Circuit
Protection
(In Amps,)
Min. Gauge
90°C Wire
Rated
Volts
Min. Gauge
90°C Wire
30
95-130
1
14 120 14
60 2
120
95-130
3 14 120 14
190-260
250
95-130 6
14 120 14190-260 3
380-520 1
500
95-130 10
14
120
208
240
14
175-235 6
190-260 6
380-520 3
1000
95-130 15
14
120
208
240
14
175-235 10
190-260 10
380-520 6
2000
95-130 30 10
120
208
240
10
14
14
175-235 20 12
190-260 15 14
380-520 10 14
3000
95-130 45 8
120
208
240
8
12
12
175-235 25 10
190-260 25 10
380-520 15 14
5000
95-130 80 4
120
208
240
8*
10
10
175-235 40 8
190-260 40 8
380-520 20 12
7500
190-260 60 6
120
208
240
4
380-520 30 10 8
321
654
7 98