WTH-120/B/R Series
Paperless Datasheet	01
Model & Ordering Code	01
Certificates of Products	01
More Package	02
Technical Data	03
Surge Protection Connection Diagram	04
Dimensions	04
Remote Contacts (Dry Contacts)	05
Fault Indication	05
Common Terms and Definitions	06
How to choose a suitable Uc(MCOV) value	06
AC Network Connection Diagram	07
Difference mode & Common mode Connection Diagram	08
Selection of back-up fuse	09
Selection of back-up circuit-breaker	09
Application	10
N-PE Module	11
3P + NPE Combintion Package	11
1P + NPE Combintion Package	11
FAQ & Help	12
Download WatchfulEyE Official App	13
After-sale Services	13
I have a question	13

Paperless Datasheet

Going green and protecting environment is manufacturers' responsibility. Each WatchfulEyE product has a link of downloading data sheet on its enclosure:
http://datasheet.watchfuleyesolutions.com/US120305x3.html

3D file download

Model & Ordering Code

Certificates of Products

Note: MCOV 385VAC UL listed only

More Package

Description

In accordance with: IEC/EN61643-11 - Class I and UL1449 Type 4 Location
Location of use: main sub-distribution boards
One-piece compact design with minimized volume but maximized capability of Class I surge protection.
Internal thermal disconnect devices help ensure safe or at end-of-life

WTH-120/B/R/1P Series Technical Data
Requirement Class to IEC/EN61643-11	Class I
IEEE Category Rating	C & B
Nominal Discharge Current (In)	60kA
Max. Discharge Current (Imax)	120kA
Pulsed Current (Iimp)	15kA
Protection Modes	L-PE, N-PE
Protective Element	MOV
Follow Current (If)	NO
Response Time (tA)	<5ns
Leakage Current (at 75%U1mA)	<20μA
Thermal Protection	YES
Protection Rating (IP Code)	IP 20
Short Circuit Current Ratings (SCCR)	25kA rms
Max. Back-up Fuse (if mains >160A)	160A gL (circuit-breaker: <100A)
Surge Life at 3kA (8/20μs)	>5000 events
Temperature Range	- 40°F to 176°F (-40°C to 80°C)
Relative Humidity	0% to 95% noncondensing
Maximum Operating Altitude	10,000 feet (3000m)
Terminal Cross Section	35mm² (solid) / 25mm² (stranded)
Stripping Length Contacts	0.6inches (15mm)
Terminal Screw Torque	Max. 3.5Nm
DIN Rail EN60715	35mm top-hat rail
Dimensions DIN 43880	36mm (2TE)
Housing Material	Thermoplastic (UL94 V-0)
Housing Design	One-piece compact design
Net Weight Per Unit	0.46Lb (209g)

Surge Protection Connection Diagram

Indication of three levels of surge protection
With three MOVs' protection at the same time, the module can realize Class I surge protection; in case that two of the indicator windows indicates red, it can still meet Class II surge protection requirements.

Maximum Continuous Operating Voltage (MCOV/Uc)	275VAC	320VAC	385VAC	420VAC
Voltage Protection Level (Up)	2.1kV	2.2kV	2.4kV	2.5kV
Residual Voltage (Ures)	1.0kV	1.1kV	1.2kV	1.4kV

Dimensions

Remote Contacts (Dry Contacts)

1: COM (Common)
2: NC (Normally Close)
3: NO (Normally Open)

Fault Indication

Common Terms and Definitions

1. Normal operating voltage rating (Un)
2. Maximum Continuous Operating Voltage (Uc/MCOV):
Maximum r.m.s. voltage, which may be continuously applied to the surge protective device's mode of protection.
3. Nominal Discharge Current for Class II Test (In):
crest value of the current through the surge protective device having a current waveshape of 8/20μs.
4. Maximum Discharge Current (Imax):
Crest value of a current through the surge protective device having an 8/20μs waveshape and magnitude according to the manufacturers specification. Imax is equal to or greater than In.
5. Voltage Protection Level (Up):
Maximum voltage to be expected at the surge protective device terminals due to an impulse stress with defined voltage steepness and an impulse stress with a discharge current with given amplitude and waveshape.
6. Residual Voltage (Ures):
Crest value of voltage that appears between the terminals of an surge protective device due to the passage of discharge current.
7. IEEE 62.41
CATEGORY C: outdoor overhead lines, service entrance (most severe)
CATEGORY B: major feeder, short branch circuits, service panel (indoor)
CATEGORY A: long branch circuits, receptacles (indoor) (least severe)

How to choose a suitable Uc(MCOV) value

Note: Uc >1.15Un
The relationship between two parameters Uc and Up of a surge protective device is proportional.
If Uc is small, the value of Up is also small; surge protective devices with smaller Up can provide better surge protection.
Whether to choose smaller Uc depends on the voltage stability of the grid.
If you choose surge protective devices with smaller Uc for the grid with instable voltage, the surge protective devices will frequently work while the grid voltage fluctuates, resulting in shortening surge protective device's product life.
If you choose larger Uc, and the value of Up is accordingly large, the surge protective efficiency will not be so fine.
If you are unsure of the voltage stability of the grid,
it is suggested to calculate MCOV(Uc) using the following formula: √ 2  Un < Uc < √ 3 Un

AC Network Connection Diagram (1/2)

AC Network Connection Diagram (2/2)

Difference mode & Common mode Connection Diagram

Common mode:L-PE, N-PE surge protection
Difference mode:L-N surge protection

Selection of back-up fuse

Selection of back-up circuit-breaker

Application

Key
1. Origin of the installation
2. Distribution board
3. Distribution outlet
4. Main earthing terminal or bar
5. Surge protective device, class I or II tested
6. Earthing connection (earthing conductor) of the surge protective device
7. Fixed equipment to be protected
8. Surge protective device, class II tested
9. Surge protective device, class II or class III tested
10. Decoupling element or line length
F1, F2, F3 overcurrent protective disconnectors
NOTE Refer to IEC 61643-12 for further information.

N-PE Module

WTH-165/G module integrates High-Energy GDT, no leakage current. It pairs WTH-120/B/R series surge protector, combined into N-PE protection mode, the two modules are the same in dimension and shape, and are connected with a dedicated bus-bar to achieve a perfect combination.

WTH-165/G Technical Data
Max. continuous operating voltage (Uc)	255V
Nominal Discharge Current (In)	80kA
Max. Discharge Current (Imax)	165kA
Pulsed Current (Iimp)	52.5kA
Voltage protection level (Up)	1.5kV
Protection Modes	N-PE only
Protective Element	High Energy GDT
Follow Current (If)	100A rms
Response Time (tA)	<100ns
Net Weight Per Unit	0.4Lb (180g)

3P + NPE Combintion Package

1P + NPE Combintion Package

FAQ & Help

1. What should I do if I can't find the paper manual in the product packaging?
Watchful Eye products is committed to going green with paperless data sheets. On the side of each product enclosure is an engraved link with URL for downloading paperless data sheet and QR code of the website. If you need the paper data sheet, you can open the link and print the data sheet by yourself.

2. The advantages of fault indication windows?
If surge protection fails, the fault indication windows will turn red, thus it can be seen intuitively, and the surge protective device can be replaced in time to avoid damage to the equipment caused by a second surge.

3. What instruments can be used to test whether its surge protection function is normal or not?
Test with a Watchful Eye surge protector tester

4. Can you list more applications?
Power supply panel, whole house

Download WatchfulEyE Official App

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After-sale Services

Watchful Eye provides a 5-year quality warranty globally.

I have a question