Minor Rant

Status
Not open for further replies.

kwired

Electron manager
Location
NE Nebraska
Yes, I get all that.
My point was why rate it for a system that is used hardly anywhere?
Doesn't seem to make sense.
What am I missing?
240 volts single phase is very popular system voltage. If this is a single phase machine, I'd kind of expect that to be the primary intended supply voltage. The major load of this machine should be a heating element. Computer, printer etc. may even be supplied via a separately derived system within the machine. If so one could easily design that with a 208 and 240 volt primary tap on the supply transformer, HVAC equipment commonly does have such a tap on control transformers.

In the end it all comes down to the fact there is no 230-240 volts available anywhere on campus without using an additional transformer. This autoclave is a fairly sophisticated model that in addition to resistive heating elements, it contains a small computer, a printer, water pumps, electronic/electric door lock, and a fan.
Do those other loads run directly from the supply voltage? I bet they are transformed and even rectified to DC volts. Water pump may be more likely to run on supply volts than most the other items.
 

kwired

Electron manager
Location
NE Nebraska
Yes, I'm aware of that (120-0-120) but this from the op

is the basis of his grouse.
240 volts is rare to the OP and not necessarily the manufacturer of the equipment in question. IOW he (his employer) is not their only client;)

We still don't know if there was option to purchase a 208 volt unit and whoever was responsible for purchasing dropped the ball. Maybe the 208 volt unit cost more, but purchasing agent doesn't understand installation will also cost more if you need to transform to 240.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
240 volts is rare to the OP and not necessarily the manufacturer of the equipment in question. IOW he (his employer) is not their only client;)

We still don't know if there was option to purchase a 208 volt unit and whoever was responsible for purchasing dropped the ball. Maybe the 208 volt unit cost more, but purchasing agent doesn't understand installation will also cost more if you need to transform to 240.
Yes, maybe the buyer dropped a goolie. The OP should have at least have sight of the manufacturer's quotation, the subsequent purchase order and at least initialed it. As I mentioned earlier in the thread, everything in writing.

Things are simpler here - and I like it that way...........:cool:
 

itasca_mn

Member
Location
Minnesota
240 volts is rare to the OP and not necessarily the manufacturer of the equipment in question. IOW he (his employer) is not their only client;)

We still don't know if there was option to purchase a 208 volt unit and whoever was responsible for purchasing dropped the ball. Maybe the 208 volt unit cost more, but purchasing agent doesn't understand installation will also cost more if you need to transform to 240.

In reply to your first statement: Of course we are not the manufacturer's only client, but we are indeed typical of the majority of their clients in the USA. 240 volts is indeed rare at facilities that would typically use this autoclave unit.

Second part: I thought I answered that a few posts back, but maybe not. The supplier for this scientific equipment has a special preferred vendor contract with MNSCU universities, thus was/is favored over other vendors. They had no 208 volt option. The department that ordered the unit, did in fact confer with me prior to ordering.
 

kwired

Electron manager
Location
NE Nebraska
In reply to your first statement: Of course we are not the manufacturer's only client, but we are indeed typical of the majority of their clients in the USA. 240 volts is indeed rare at facilities that would typically use this autoclave unit.

Second part: I thought I answered that a few posts back, but maybe not. The supplier for this scientific equipment has a special preferred vendor contract with MNSCU universities, thus was/is favored over other vendors. They had no 208 volt option. The department that ordered the unit, did in fact confer with me prior to ordering.
Has anyone requested they make a 208 volt unit? Told them they may look into a different vendor that will build them what they want?

They can build whatever they want if they know they can get away with it.

Do they offer to sell a buck/boost transformer or do they say it must be supplied by others?

Is heating element(s) the only direct connected loads to input volts (is there a control transformer and or DC converter)?
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
Second part: I thought I answered that a few posts back, but maybe not. The supplier for this scientific equipment has a special preferred vendor contract with MNSCU universities, thus was/is favored over other vendors. They had no 208 volt option. The department that ordered the unit, did in fact confer with me prior to ordering.
But still ordered a 240V unit?
If you are stuck with it, you are stuck with it, I guess. An autransformer would seem to be your only option. What sort of power is involved?
 

itasca_mn

Member
Location
Minnesota
240 volts single phase is very popular system voltage. If this is a single phase machine, I'd kind of expect that to be the primary intended supply voltage. The major load of this machine should be a heating element. Computer, printer etc. may even be supplied via a separately derived system within the machine. If so one could easily design that with a 208 and 240 volt primary tap on the supply transformer, HVAC equipment commonly does have such a tap on control transformers.

Do those other loads run directly from the supply voltage? I bet they are transformed and even rectified to DC volts. Water pump may be more likely to run on supply volts than most the other items.

Yes, 240 volts single phase is a popular system voltage overall, but not at facilities typical for this type of machine in the USA. A machine like this autoclave will most often be used at facilities that have 3-phase, 120/208 volt, WYE connected systems, e.g. hospitals, clinics, science laboratories, etc. Even though this machine is a single phase machine, it will most often be fed from a single phase of a 3-phase system.
 

kwired

Electron manager
Location
NE Nebraska
Yes, 240 volts single phase is a popular system voltage overall, but not at facilities typical for this type of machine in the USA. A machine like this autoclave will most often be used at facilities that have 3-phase, 120/208 volt, WYE connected systems, e.g. hospitals, clinics, science laboratories, etc. Even though this machine is a single phase machine, it will most often be fed from a single phase of a 3-phase system.
I understand, but if the maker only makes it in 240 volt versions, seems the rant should be with them. If you had options for other voltages, then whoever was involved in purchasing is to blame.

If the maker would happen to be in another country and also sells to European and other places with 240 volts single phase - a little understandable that one machine might work in many markets.

You tied to this manufacturer for some reason? If not tell them you are going to someone that makes what you want in the future.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
You tied to this manufacturer for some reason? If not tell them you are going to someone that makes what you want in the future.
Spot on. Tell them where to go. But maybe the OP isn't in a position to exert that authority.
 

ismaelyork

New User
Location
AU
Occupation
Mathematical Science Teacher, Postsecondary
It's because not everything is made for US customers. Anyway, those who order equipment may not know the difference between voltage, that's pretty common in the universities like yours, lol. Probably this manufacturer works for the EU market mostly, and not the US, and you should change your manufacturer to another. I learned that when I took my electrician courses, see this to check the details. Anyway, I understand that you may not have such authority, but at least you can talk with higher staff about that. They will probably listen to you and fix the issues for the future.
 

garbo

Senior Member
I'm perplexed. I work in the electrical department at a Minnesota State University. Over the years, several various departments on campus have ordered new tools and lab equipment. Most of this equipment is intended for use in large commercial applications. Examples of some of these machines are, milling machines, CNC, Autoclaves, Spectrum analyzers, etc. It seems to never fail that these devices are designed to operate at 230-240 volts, and often times the manufacturer will not want this equipment connected to 208 volts. I just recently connected a new Autoclave, that requires single phase 230-240 volts. The manufacturer provided an optional boost transformer to bring the voltage up to acceptable levels. Why would these machines be designed so often to operate at 240 volts, when they have to know that a majority of the time they will be used at facilities that most often will only have 3-phase WYE power?
I agree with you 100%. Its easier for companies to only manufacture 1 machine that some can be used on either 208 or 240 volts. The problem that I have came across with 240 volt motors running on 208 volts is during brown outs or hot summer days and have seen the voltage dip to 190 volts. I did a lot of work in machine shops where they had 208 volt services up to 800 amps. Their CNC machines were ordered for 208 volts and never had to use buck boost transformers. Its cheaper for rich ultility companies to have 120/208 3 phase service so they can supply all power thru only 1 meter & 1 transformer.A lot of the buck boost transformers are always energised just sitting there wasting electricity when load is off.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
This thread is 2 years old, so it is being locked.

Please start a new thread if you would like to continue the discussion.
 
Status
Not open for further replies.
Top