<p>As 0scar noted, this looks suspiciously <em>like</em> a JST connector, but the left one is not a JST RCY connector and it is neither one of the common <a href="https://www.jst-mfg.com/product/detail_e.php?series=199" rel="noreferrer">JST PH</a> nor <a href="https://www.jst-mfg.com/product/detail_e.php?series=277" rel="noreferrer">JST XH</a>, JST manufacturer pages show. In fact, it's not a <a href="https://www.jst-mfg.com/product/search_e.php?type=1&amp;id=11&amp;page=1" rel="noreferrer">wire-to-wire JST</a> connector. The <a href="https://www.bqstore.nl/de/bq/77-BQ-Heizpatrone-40W-mit-JST-Stecker-8436545516805.html" rel="noreferrer">BQ-store claims</a> it is a 2.5 mm JST connector, but JST has some 10 dozen different types of connectors, some three dozen of them with a 2.5 mm pitch.</p>
<h2>&quot;JST Quick&quot; / JST RCY</h2>
<p><a href="https://www.jst-mfg.com/product/detail_e.php?series=521" rel="noreferrer"><img src="https://i.sstatic.net/2TWZM.png" alt="enter image description here" /></a></p>
<p>This one is rated 3A, and looks like the connector on the right, the thermistor one. So if you need to fix that, you know what to get for that.</p>
<h2>So what it is?</h2>
<p>The connector however looks at <em>first glance suspiciously</em> like this one:
<a href="https://i.sstatic.net/HKAwN.png" rel="noreferrer"><img src="https://i.sstatic.net/HKAwN.png" alt="enter image description here" /></a></p>
<p>I found this product on several warehouses, listed as <code>2-PIN CONNECTOR W/HEADER, .10&quot;</code>, and even found a <a href="https://www.allelectronics.com/mas_assets/media/allelectronics2018/spec/CON-242.pdf" rel="noreferrer">specsheet</a>. Those products appear, in design, to be based on the <a href="https://www.molex.com/molex/products/part-detail/crimp_houaings/0022013027" rel="noreferrer"><strong>Molex KK 254</strong></a> from the 2659 series. A genuine Molex 2659-series connector is rated for up to <a href="https://www.molex.com/pdm_docs/ps/PS-10-07-001.pdf" rel="noreferrer"><strong>2.5 Ampere</strong></a>, and looks <em>somewhat</em> similar.</p>
<p>However, the shop did claim it is a JST 2.5 mm pin, and they give a side view:</p>
<p><a href="https://i.sstatic.net/5UEE8.png" rel="noreferrer"><img src="https://i.sstatic.net/5UEE8.png" alt="enter image description here" /></a></p>
<p>That is <strong>not</strong> a Molex KK. It appears more similar to a JST NV, which however has a 5 mm distance between the peg centers (= pitch) and it's rated for 10 A (or 120 W at 12V!). While matching in <em>style</em> it does not match in measurements - as OP confirmed, there's a very close to a 4 mm pitch (+- measurement tollerance) on the connector. So it's not an NV, but something os similar style.</p>
<p><a href="https://www.jst-mfg.com/product/detail_e.php?series=186" rel="noreferrer"><img src="https://i.sstatic.net/TNbT1.png" alt="enter image description here" /></a></p>
<p>But then it has to be the VH! The VH series has a 3.98 mm pitch, it has that latch and it is rated 10 A, for 120 W at 12 V. In fact, the pins on the Hotend seem to be B2P-VH, matching VHR-2N or VHR-2M &quot;female&quot; adapters.</p>
<p><a href="https://www.jst-mfg.com/product/detail_e.php?series=262" rel="noreferrer"><img src="https://i.sstatic.net/RIxNS.png" alt="enter image description here" /></a></p>
<h3>Safety?</h3>
<p>I would <strong>not</strong> trust a Molex KK 2659-series connector with a heater cartridge on a 12 V Machine! With a 12 V, 30 W Heater cartridge draws <strong>exactly</strong> 2.5 Ampere, so you'd have a safety margin of 0! That's bad design. A 40 W heater cartridge would draw 3.3 A - that's 132 % of the rating! That'd be a fire waiting to happen!</p>
<p>Only a 24 V machine could be built with a Molek KK 2659 connector and stay within the 2.5 A rating (40 W &amp; 24 V -&gt; 1.67 A, 30 W &amp; 24 W -&gt; 1.25 A) with a safety factor of about 1.5 to 2 to the rating (depending on heater cartridge).</p>
<p>However, this is a JST VH with a rating of 10 A. That means, at 12 V, it's safe for 120 W load, so plenty safe: That's a safety facor of 3, and on a 24 V machine it'd be 6. That's Perfectly safe and sane! After all we look for at least a 5 A rated connector in conjunction with a 12 V/40 W heater.</p>
<p>The more tedious variant to connect safely is to use either an even higher rated connector (requiring replacement) or a continuous wire to the board.</p>

CC BY-SA 4.0
2020-09-02T15:24:25.397Z
2020-09-02T22:13:41.920Z
2020-09-02T22:13:41.920Z
Trish
<p>I'm not really sure what the type of plug on the heater cable is. Is it a Molex KK or maybe a JST PH?</p>
<p>The printer is a <em>Prusa I3</em> Hephestos (aka BQ Hephestos). It came with this &quot;BQ HOT-END HEATCORE CLASSIC&quot; hotend from the &quot;BQ Witbox 1&quot; extruder.</p>
<p><a href="https://i.sstatic.net/Msnjw.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Msnjw.png" alt="Hotend in question" /></a></p>

CC BY-SA 4.0
2020-09-02T13:38:52.213Z
Done. But why should this help identifying the plug? If someone knows the molex or JST plug the image should be enough I think.
RomanTenger
CC BY-SA 4.0
2020-09-02T13:41:12.973Z
It might help someone with access to documentation for that printer look up the answer for you. Then again, it might not - but additional, relevant information is usually helpful. Welcome to the site, and please take the [tour](https://3dprinting.stackexchange.com/tour).
Davo
CC BY-SA 4.0
2020-09-02T14:42:21.177Z
The cable of the heater element uses a "JST male connector 2.5 mm pitch". According to the seller of the heater element.
0scar
<prusa-i3><hotend><electronics><replacement-parts><bq-hephestos>
What type of plug is this?
RomanTenger
# What type of plug is this?

(Asked by: username_0 on 2020-09-02)

I'm not really sure what the type of plug on the heater cable is. Is it a Molex KK or maybe a JST PH?

The printer is a *Prusa I3* Hephestos (aka BQ Hephestos). It came with this "BQ HOT-END HEATCORE CLASSIC" hotend from the "BQ Witbox 1" extruder.

[![Hotend in question](https://i.sstatic.net/Msnjw.png)](https://i.sstatic.net/Msnjw.png)

**Tags:** prusa-i3, hotend, electronics, replacement-parts, bq-hephestos

> **Comments:**
> **username_0**: Done. But why should this help identifying the plug? If someone knows the molex or JST plug the image should be enough I think.  
> **username_1**: It might help someone with access to documentation for that printer look up the answer for you. Then again, it might not - but additional, relevant information is usually helpful. Welcome to the site, and please take the [tour](https://3dprinting.stackexchange.com/tour).  
> **username_2**: The cable of the heater element uses a "JST male connector 2.5 mm pitch". According to the seller of the heater element.  

---

## 1 answers

### Answer by username_3 on 2020-09-02. Score: 7 | Accepted answer

As username_2 noted, this looks suspiciously *like* a JST connector, but the left one is not a JST RCY connector and it is neither one of the common [JST PH](https://www.jst-mfg.com/product/detail_e.php?series=199) nor [JST XH](https://www.jst-mfg.com/product/detail_e.php?series=277), JST manufacturer pages show. In fact, it's not a [wire-to-wire JST](https://www.jst-mfg.com/product/search_e.php?type=1&id=11&page=1) connector. The [BQ-store claims](https://www.bqstore.nl/de/bq/77-BQ-Heizpatrone-40W-mit-JST-Stecker-8436545516805.html) it is a 2.5 mm JST connector, but JST has some 10 dozen different types of connectors, some three dozen of them with a 2.5 mm pitch.

## "JST Quick" / JST RCY

[![enter image description here](https://i.sstatic.net/2TWZM.png)](https://www.jst-mfg.com/product/detail_e.php?series=521)

This one is rated 3A, and looks like the connector on the right, the thermistor one. So if you need to fix that, you know what to get for that.

## So what it is?

The connector however looks at *first glance suspiciously* like this one:
[![enter image description here](https://i.sstatic.net/HKAwN.png)](https://i.sstatic.net/HKAwN.png)

I found this product on several warehouses, listed as `2-PIN CONNECTOR W/HEADER, .10"`, and even found a [specsheet](https://www.allelectronics.com/mas_assets/media/allelectronics2018/spec/CON-242.pdf). Those products appear, in design, to be based on the [**Molex KK 254**](https://www.molex.com/molex/products/part-detail/crimp_houaings/0022013027) from the 2659 series. A genuine Molex 2659-series connector is rated for up to [**2.5 Ampere**](https://www.molex.com/pdm_docs/ps/PS-10-07-001.pdf), and looks *somewhat* similar.

However, the shop did claim it is a JST 2.5 mm pin, and they give a side view:

[![enter image description here](https://i.sstatic.net/5UEE8.png)](https://i.sstatic.net/5UEE8.png)

That is **not** a Molex KK. It appears more similar to a JST NV, which however has a 5 mm distance between the peg centers (= pitch) and it's rated for 10 A (or 120 W at 12V!). While matching in *style* it does not match in measurements - as OP confirmed, there's a very close to a 4 mm pitch (+- measurement tollerance) on the connector. So it's not an NV, but something os similar style.

[![enter image description here](https://i.sstatic.net/TNbT1.png)](https://www.jst-mfg.com/product/detail_e.php?series=186)

But then it has to be the VH! The VH series has a 3.98 mm pitch, it has that latch and it is rated 10 A, for 120 W at 12 V. In fact, the pins on the Hotend seem to be B2P-VH, matching VHR-2N or VHR-2M "female" adapters.

[![enter image description here](https://i.sstatic.net/RIxNS.png)](https://www.jst-mfg.com/product/detail_e.php?series=262)

### Safety?

I would **not** trust a Molex KK 2659-series connector with a heater cartridge on a 12 V Machine! With a 12 V, 30 W Heater cartridge draws **exactly** 2.5 Ampere, so you'd have a safety margin of 0! That's bad design. A 40 W heater cartridge would draw 3.3 A - that's 132 % of the rating! That'd be a fire waiting to happen!

Only a 24 V machine could be built with a Molek KK 2659 connector and stay within the 2.5 A rating (40 W & 24 V -> 1.67 A, 30 W & 24 W -> 1.25 A) with a safety factor of about 1.5 to 2 to the rating (depending on heater cartridge).

However, this is a JST VH with a rating of 10 A. That means, at 12 V, it's safe for 120 W load, so plenty safe: That's a safety facor of 3, and on a 24 V machine it'd be 6. That's Perfectly safe and sane! After all we look for at least a 5 A rated connector in conjunction with a 12 V/40 W heater.

The more tedious variant to connect safely is to use either an even higher rated connector (requiring replacement) or a continuous wire to the board.


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