HWS15A

Direct current power unit
List ofproducts

WO81

HWS15A
Direct current power unit
This instrument is used to drive a fine differential pressure sensor or fine differential

WO71

pressure transmitter with 12 to 24 V DC power specification.

FR51A

MS99

MS99S

MS61A-RA

QDP33

EMD8A

EMD7

EMT1

EMTGP1

HWS15A

EMT1H

EMT6

EMP5A

EMRT1

HWS15A

Accessories
Application

Precautions

Product code

Maintenance

HWS15A-24/A◆When making an inquiry or placing an order, specify the above
product code.
◆The DC power device HWS15A is a product manufactured by TDKLambda Corporation.

99RoHS

HWS15A

Direct current power unit
HWS15A

List ofproducts

Specifications

WO81

HWS15A-24/A

ModelInput voltage

85 to 265 V AC (47 to 63 Hz) or 120 to 370 V DC

Output voltage

24 V DC

Maximum output
current

0.65 A

Output variation at
operating ambient
temperature

0.02%/°C or lower

WO71

FR51A

Overcurrent protection

0.68 A and higher

Operating ambient
temperature−10°C to +70°C (−10°C to +50°C: 100%, +60°C: 80%, +70°C: 60%)

Operating ambient
humidity

30% to 90% RH (no condensation allowed)

Withstand voltageBetween input and FG: 2 kV AC (20 mA), between input and output: 3 kV AC (20 mA)
Between output and FG: 500 V AC (100 mA), each for one minuteInsulation resistance

100 MΩ or higher (between output and FG: 500 V DC, 25°C, 70% RH)

MassApprox. 210 g

MS99

MS99S

◆For use environment, refer to page 118.

MS61A-RA

Terminal connection diagram

FGAC85V
to265V

2XWSXWGLVSOD\/(' JUHHQ
5-M3.55&RYHU
1 ＋V,QSXWRIWR+]$&

7.3

2 −V

QDP33

For AC input.QREIRUYDULDEOHRXWSXWYROWDJH

43＋24V（10.1）

GND

External shape drawing

21−＋

9'&RXWSXW*URXQGLQJ3 FG

EMD8A

For DC input

5（14）'&LQSXW

31.5±1)RUPRXQWLQJ0'HSWKRIPPDWPD[LPXP/HIWVLGHIDFH

4GND

EMT13＋24V

FG

5 AC(N)

DC
120V
to370V（17） 8.44 AC（Ｌ）

2

EMTGP11−*URXQGLQJ＋

9'&RXWSXW

EMT1H

Terminal screw tightening torque: 1.6 N·m
Do not tighten to a torque that exceeds the specified value
because doing so breaks the instrument body.

！
Caution82±1（67.5）
7.3

68±0.5

When there are multiple fine differential pressure transmitters

1 EMT1819MAX

62±0.580±182)RUPRXQWLQJ0'HSWKRIPP
DWPD[LPXP

24V

（5）

150.65A

67±0.5

831.5±117

HWS15A-24/A（5.5）−EMT1343424V DC＋＋4‒20mA−＋−1DPHSODWH

EMT6EMP5A

0XOWLSOHWZRZLUHW\SHILQHGLIIHUHQWLDOSUHVVXUHWUDQVPLWWHUVFRQQHFWLRQGLDJUDP)LQHGLIIHUHQWLDOSUHVVXUHWUDQVPLWWHU（10）

EMD715 EMT134＋−2 '&SRZHU 51VRXUFH

HWS15A
33RZHULQSXW

4*URXQGLQJ＋ 5HFHLYLQJ−GHYLFH＋ 5HFHLYLQJ−GHYLFH＋ 5HFHLYLQJ−GHYLFH

EMRT1HWS15A
12Accessories
Application

15Precautions
Maintenance

5HOD\WHUPLQDOThis DC power unit <HWS15A> can supply 24 V
DC power to up to 15 two-wire type fine differential
pressure transmitters. Provide relay terminals for DC
power distribution use as shown in the figure above,and supply power to each transmitter. The user should
prepare the relay terminals for distribution use.

100Combination
List ofproducts

WO81

WO71

Combination with fine differential pressure transmitter
When you use a fine differential pressure transmitter in combination with a displaying instrument or other device, select them by referring tothe combination table below.

Transmission
methodFine differential pressure transmitter

Displaying
instrument

Relevant device
Airflow rate measurement

FR51A

MS99

EMT1A

MS61A-RA

EMT6

EMTGP1B

EMTGP1A
Intrinsically safe type

QDP33

EMT1HIntrinsicallysafe circuit

EMD8A*Installation at hazardous locations

EMD7

EMT1

EMTGP1

EMT6

EMP5A

EMRT1

HWS15A

Accessories
Application

Precautions
Maintenance

113

Receiving
instrument

HWS15A

EMRT1

EMP5A

〜〜〜

If a DC power circuit is
not incorporated into
the receiving device,
use the device in
combination with thispower unit.

For airflow ratemeasurement, a squareroot calculation circuit isnecessary.
If a square root
calculation circuit is
not incorporated into
the receiving device,
use the device in
combination with thiscalculator.

The receivinginstrument EMP5A is
incorporated with a
DC power circuit and asquare root calculation
circuit.

Adjustment meter〜*We do not handle
adjustment meters.

Four-wire
type
EMT1B

EMT1A

EMT1H

Square root
calculator

EMT1B

MS99S
Two-wiretype

Direct current
power unit〜◆〜 : Represents power voltage of 100 V AC 50/60 Hz. (For the power voltage input range, refer to the page describing each product.)◆Be sure to combine our receiving instrument with a fine differential pressure transmitter with the same pressure range as that on the nameplate attachedto the body of the receiving instrument.
◆Please be advised that if a failure occurs because of the combination of our product with a device from another manufacturer, we shall assume noresponsibility. Therefore, pay due attention to the functions and circuits of the device.
◆When installing a device as an intrinsically safe device, pay attention to hazardous and non-hazardous locations. (Refer to page 87)◆When you use these products for airflow rate/airflow speed measurements, we need to obtain the specifications of the pressure detection side. Fill out
the airflow rate/airflow speed specification document preparation sheet on page 15, and inform us of the data.

Warranty■Warranty period
The warranty period for our product is one (1) year from delivery to the location specified by the orderer who makes a direct transaction
with us.

■Scope of warranty
If any failure or defect attributable to us becomes clear during the above warranty period, we will repair the product or supply asubstitute product free of charge. However, even during the warranty period, we will exclude the product from the scope of the warranty
if the failure or defect corresponds to any of the following:(1) The failure or defect was caused by an unreasonable condition, environment, handling, or usage not mentioned in theinstruction manual, specifications, and our product catalog.
(2) The failure or defect was caused by a factor other than our product.
(3) The failure or defect was caused by a modification or repair conducted by a party other than us.
(4) The failure or defect was caused by an event that could not be foreseen at the scientific and technical levels at the time ofproduct shipment from us.
(5) The failure or defect was caused by an external factor not attributable to us, such as acts of God and disasters.
Please note that the warranty mentioned here means the warranty for our individual product, and damage provoked by a failure or
defect of the product is excluded from the scope of the warranty.
*This warranty is valid only in Japan.

Application and usage
Our products are designed and manufactured as general-purpose instruments for general industries.
Therefore, our products are not intended for the following uses, and our products used in such a manner are outside the scope ofapplication.
(1) Equipment that is anticipated to greatly affect lives and properties, such as nuclear power generation, aviation, railways, marinevessels, vehicles, and medical devices(2) Utilities that include electricity, gas, and service water(3) Use in outdoor locations and under similar conditions or environments other than those stipulated in the instruction manual(4) Usage to which considerable safety consideration and attention equivalent to (1) and (2) above need to be given

Service■Scope of service
Because the product price does not include service expenses, such as the dispatch of engineers, we will separately charge for theexpenses in the following cases:(1) Instruction for installation and adjustment and a witnessed test run(2) Maintenance inspection, adjustments, and repairs(3) Technical guidance and technical education(4) Witnessed inspections of products at our factory<<Note>> The product specifications and information in this catalog are subject to change without prior notice for product improvement orother reasons.

●For order placement, contactGeneral
agent

Manostar Shop Co., Ltd.

1-2-3 Nishishiriike-cho, Nagata-ku, Kobe City, Hyogo 653-0031
TEL. +81-78-621-7000 FAX. +81-78-621-7788

Manufacturer

Yamamoto Electric Works Co., Ltd.

1-2-3 Nishishiriike-cho, Nagata-ku, Kobe City, Hyogo 653-0031
TEL. +81-78-631-6000 FAX. +81-78-631-6020

SEPTEMBER 2021 YAMAMOTO ELECTRIC WORKS CO., LTD., JAPAN