Resources for Retail Electric Suppliers Frequently Asked Questions These FAQs supplement the information contained in the Ameren RES Handbook as well as the Supplier Terms and Conditions for AmerenCILCO, AmerenCIPS, and AmerenIP. Should you have any questions or comments regarding the information below, please contact the Ameren Transmission Services Business Center at 888.263.7361. Note that additional FAQs will periodically be added to this page – so be sure to check back occasionally.
Customer Enrollment, EDI, and Billing Issues
1.	Q.	What is the Ameren billing window?
	A.	The Ameren billing window is a four business day period of time that extends from two business days prior to an account’s scheduled meter reading date to one business day after an account’s scheduled meter reading date. On-cycle enrollments always occur within an account’s billing window and may occur on a non-business day if the non-business day falls within the billing window. To view a table listing Ameren’s scheduled meter reading dates, please see Ameren’s Scheduled Meter Reading Dates page.
2.	Q.	What is a service point?
	A.	A service point consists of metered or unmetered load that is assigned to a specific Ameren rate. A service point containing metered load can have one or more meters associated with it. An account may have multiple electric service points. Typically, an account that has multiple electric service points has a different rate assigned to each of those service points. For example, an account with a DS2 service point may also have a DS5 (lighting) service point. However, it is possible for an account to have multiple electric service points that are each on the same rate.
3.	Q.	How is an account’s enrollment effective date determined?
	A.	First, note that enrollments are effectuated at the service point level, not the account level (see FAQ number 2 above for a definition of “service point”). Thus, an on-cycle enrollment for an account with multiple electric service points could have a slightly different enrollment effective date for each service point on the account. On-cycle enrollment of a scalar metered service point:     Enrollment is effectuated when the service point’s meter data is collected – which will     occur within the four business days that comprise the account’s billing window. The     actual time of the enrollment could be anytime during the day that the meter data is     collected. Note that an on-cycle enrollment may occur on a non-business day if the     non-business day falls within the billing window. On-cycle enrollment of an interval metered service point:     Enrollment is effectuated when the service point’s meter data is collected – which will     occur within the four business days that comprise the account’s billing window. The     actual time of the enrollment could be anytime during the day that the meter data is     collected. Note that an on-cycle enrollment may occur on a non-business day if the     non-business day falls within the billing window. Off-cycle enrollment of a scalar metered service point:     Enrollment is effectuated as of the very end of the day (i.e. 23:59:59) of the date     requested. An actual meter reading on the off-cycle enrollment date is not taken.     Instead, for the first billing period that includes the date of the off-cycle enrollment,     usage is prorated for the time between when the enrollment is effectuated and the     date on which the meter is actually read. Off-cycle enrollment of an interval metered service point:     Enrollment is effectuated as of the very end of the day (i.e. 23:59:59) of the date     requested.
4.	Q.	Why does Ameren’s EDI response to an on-cycle enrollment DASR indicate a specific enrollment effective date, yet the actual start date as shown in the EDI 867 (when the account bills for the first time after the enrollment) is sometimes slightly different?
	A.	For an on-cycle enrollment, Ameren returns the account’s scheduled meter reading date as the enrollment effective date. However, since Ameren has a four business day billing window (extending from two business days prior to an account’s scheduled meter reading date to one business day after an account’s scheduled meter reading date) the actual enrollment effective date can occur anytime – including a non-business day – within that window. Since Ameren doesn’t know – at the time the on-cycle enrollment DASR is submitted – what the specific enrollment effective date is going to be, the scheduled meter reading date is returned as a placeholder for the enrollment effective date. Again, the actual enrollment effective date could vary by up to two business days prior to the account’s scheduled meter reading date to one business day after the account’s scheduled meter reading date.
5.	Q.	What happens if an enrollment requesting the Single Billing Option (SBO) is submitted for an account that is on budget billing with Ameren?
	A.	Ameren does not allow an account to be on both SBO and budget billing at the same time. When Ameren receives an enrollment requesting SBO for an account that is on budget billing, the account is removed from budget billing.
6.	Q.	How is a budget balance due handled on an account that is placed on the Single Billing Option (SBO) right after being removed from budget billing?
	A.	A budget balance due develops when a customer has paid the predetermined budget billing amount each month, but the net of the budget billing amounts paid over a given period of time has been less than the cost of the account’s actual usage over that same period of time. When such an account is removed from budget billing and placed on SBO, the budget balance due will be billed by Ameren directly to the customer and will not be communicated to the RES in an EDI 810 transaction.
7.	Q.	What happens if an enrollment requesting the Single Billing Option (SBO) is submitted for an account that is in arrears?
	A.	Ameren does not allow an account that is in arrears to be enrolled to RES supply with SBO billing. When Ameren receives a RES enrollment requesting SBO for an account that is in arrears, the enrollment is rejected.
8.	Q.	What happens if an enrollment requesting the Single Billing Option (SBO) is submitted for an account that is on summary billing with Ameren?
	A.	Summary billing is an Ameren billing option in which numerous bills for a specific customer are consolidated into one. An account cannot be on both summary billing and SBO at the same time. When Ameren receives an SBO enrollment for an account that is on summary billing, the account is removed from summary billing and placed on SBO.
9.	Q.	What happens if an enrollment requesting the Single Billing Option (SBO) is submitted for an account that has both electric and gas service points?
	A.	When Ameren receives an enrollment requesting SBO for an account that has both electric and gas service points, Ameren will split the gas service point off of the account and assign a new account number to it. The electric service point(s) will remain associated with the original account. If, at the time of the enrollment, the account is on Direct Pay (payment of monthly bill is automatically deducted from the customer’s bank account), then the Direct Pay will be transferred to the newly-created gas account and will be removed from the original account.
10.	Q.	Can an account be enrolled off-cycle to the Single Billing Option (SBO)?
	A.	If Ameren receives an off-cycle enrollment requesting SBO, then the account will be defaulted to the dual billing option for the first billing period that includes the enrollment effective date. After this first billing period, Ameren will then change the billing option for the account to SBO.
11.	Q.	If a RES submits an account-level enrollment DASR for an account that has a DS5 (lighting) service point in addition to another electric service point, will the DS5 (lighting) service point be enrolled along with the other electric service point?
	A.	Yes. An account-level enrollment DASR will switch all electric service points on an account – including any lighting service points – to RES supply.
12.	Q.	What is calendar-month billing?
	A.	Some accounts, typically larger commercial or industrial accounts, are calendar-month billed. With calendar-month billing, any non-lighting electric service points on such accounts are billed in calendar-month increments. Note that if a calendar-month billed account has a lighting service point, then the lighting service point may not necessarily bill in calendar-month increments (although the non-lighting service points will). There are three types of calendar-month billing: beginning of the month, middle of the month, and end of the month. The vast majority of calendar-month billed accounts are end of the month. This means that the non-lighting service points on such accounts always bill through the last calendar day of each month. There is a small number of beginning of the month calendar-billed accounts. The non-lighting service points on these accounts bill through the first day of each month. Middle of the month calendar-billed accounts are extremely rare. The vast majority of calendar-month billed accounts are assigned to bill group 21, although there are some in bill groups 20 and 01. Note that these three bill groups are not set aside just for calendar-month billed accounts. In other words, most accounts that are assigned to these bill groups are not calendar-month billed.
13.	Q.	When should an enrollment DASR or drop DASR be submitted for a calendar-month billed account?
	A	For a calendar-month billed account, the account’s scheduled meter reading date is not used as the point from which the seven calendar day enrollment/drop blackout period is calculated. Instead, for an end of the month calendar-billed account, an enrollment or drop must be received by Ameren no later than 5:45 p.m. Central Prevailing Time seven calendar days prior to the last calendar day of the month. For a beginning of the month calendar-billed account, an enrollment or drop must be received by Ameren no later than 5:45 p.m. Central Prevailing Time seven calendar days prior to the first calendar day of the month. In cases where the seventh calendar day falls on a weekend day or a holiday, the enrollment or drop must be received by Ameren no later than 5:45 p.m. Central Prevailing Time the first business day prior to that weekend day or holiday.
14.	Q.	What is the procedure if a RES wishes to enroll a brand new account to be effective as of the start date of the new account, but Ameren has either not yet created the account number or has not yet attached a service point and meter to the account?
	A.	For various reasons, Ameren may not create the new account number in time for the RES to submit an enrollment DASR that would be effective as of the start date of the account. In addition, sometimes Ameren creates a new account, but there is a delay in getting an electric service point and meter set up on the account. In these situations, it is expected that the RES communicate – via email to their Ameren business representative – their intention to enroll the new account. This communication must happen at least three business days prior to the date that the new account is completely set up. Once Ameren creates the new account number, the customer will need to communicate it along with an associated meter number to the RES. The RES will then need to submit an on-cycle enrollment DASR for the new account. Once the enrollment DASR is received by Ameren, Ameren will “repair” the enrollment effective date back to the start date of the new account. Note that the onus is always on the customer to keep their RES or their prospective RES aware of any changes to their accounts. This includes the splitting of an account currently served by a RES, the addition of a new account, and any changes to the anticipated start date of a new account.
15.	Q.	What is the procedure if a RES wants to enroll an account to Rider PRSS and only serve part of the account’s load?
	A.	A RES that wants to enroll an account to Rider PRSS and only serve part of the account’s load should notify their Ameren business representative prior to submitting the enrollment DASR to Ameren. This will allow Ameren time to make the necessary billing system preparations for the enrollment. The customer must also sign a written agreement with Ameren.
16.	Q.	For an account that has multiple electric service points, why can the on-cycle enrollment effective date be slightly different for each of the service points?
	A.	Enrollments are effectuated at the service point level. Since service points bill independently of each other, an on-cycle enrollment for an account with multiple electric service points can result in enrollment effective dates that vary slightly by service point. However, for all electric service points on an account, the on-cycle enrollment effective date for each of them will always fall within the four business day Ameren billing window.
17.	Q.	When an account that has multiple electric service points bills, why can the billing period be slightly different for each of the service points?
	A.	Regardless of the number of service points on an account, an Ameren delivery services bill and/or the corresponding EDI810 and EDI867 transactions are always produced together when the account bills. However, the service points that make up the account may have slightly different billing periods since service points bill independently of each other. For example, a DS5 lighting service point often bills on the first day of the four business day Ameren billing window. However, DS1, DS2, DS3, and DS4 service points may or may not bill on the first day of the Ameren billing window.
18.	Q.	How many EDI 867M transactions will be produced when a RES-supplied account bills?
	A.	EDI 867M transactions are created per service point. So, if an account has one electric service point, then only one EDI 867M will be produced each time that the account bills. If an account has a DS2 service point as well as a DS5 (lighting) service point, then two EDI 867M transactions will be produced each time the account bills. Note that the number of meters associated with a service point has no impact on the number of EDI 867M transactions that are produced.
19.	Q.	How is a subtractive meter denoted in the EDI 867 transaction?
	A.	There are a relatively small number of Ameren Illinois accounts that have one or more subtractive meters on them. The designation in the EDI 867 that a meter’s usage is subtractive can be found on the REF segment when element one is “JH” and element two is “S” (the “S” stands for “Subtractive”). Thus, a subtractive meter is denoted in the EDI 867 transaction as follows: REF*JH*S. Conversely, a typical non-subtractive meter is noted as REF*JH*A in the EDI 867 transaction (where the “A” stands for “Additive”).
20.	Q.	How may a RES change the billing option for an account that it is supplying?
	A.	A RES can change the billing option for an account via the EDI 814C transaction. The billing option change will always be effectuated for the billing period after the date requested in the EDI 814C transaction.
21.	Q.	How is interval meter data handled in the EDI 867 transaction on the spring forward and fall back days (the days leading into and out of Daylight Saving Time)?
	A.	On the spring forward day, the interval meter data in the EDI 867 will only contain 23 values, with no interval read for hour ending 3:00. For this date the hourly readings will be for hours ending 1:00, 2:00, 4:00, … On the fall back day, the interval meter data in the EDI 867 will contain 25 values, with two interval reads for hour ending 2:00. For this date the hourly readings will be for hours ending 1:00, 2:00, 2:00, 3:00, …
22.	Q.	Why can the very last interval read contained in an EDI 867 transaction for a given account be for the same hour as the first hour shown in that same account’s EDI 867 transaction for the following billing period?
	A.	For most interval metered accounts, reads are taken at the end of each hour, and 15, 30, and 45 minutes after each hour. However, Ameren does not provide 15 minute interval data in the EDI 867 transaction. Instead, Ameren provides hourly interval data in the EDI 867. Since a billing period can end in-between hours, Ameren accounts for this by showing that hour twice – once in two separate EDI 867 transactions. The first time that the hour is shown is as the final hour of a billing period. The usage will not represent a full hours’ worth of data, but will instead represent the usage up through when the read was taken. For example, if the final read for a billing period was taken at 14:30, the usage shown in the EDI 867 for hour ending 15:00 will only be for the first 30 minutes of the hour. The second time that the hour is shown is as the first hour in the EDI 867 for the next billing period. The usage will not represent a full hours’ worth of data, but will instead represent the usage from the time of the end read of the previous billing period through the end of that hour. For example, if the last read from the previous billing period was taken at 14:30, the usage shown in the EDI 867 for hour ending 15:00 will only be for the final 30 minutes of the hour.
23.	Q.	What happens if a RES-supplied customer declares bankruptcy?
	A.	If a RES-supplied customer declares bankruptcy, then each Ameren account associated with that customer will be finaled (closed) – thus triggering the generation of one or more EDI 814D transactions to the customer’s RES. If the customer stays in business despite the bankruptcy and wishes to continue with electric service, then a new account or accounts will be set up for the customer. The new account(s) will automatically be assigned to the RES that was supplying the finaled account(s). An EDI814E transaction(s) will be sent to the RES to reflect the enrollment of the new account(s).
24.	Q.	Why is it that some service point Peak Load Contribution (PLC) values are zero?
	A.	A PLC is a given service point’s contribution to the Ameren Illinois annual system peak. Currently, Ameren calculates PLCs once per year – typically toward the end of a calendar year. These PLCs then become effective June 1st of the following year. Any new service point that is created after PLC calculations are made gets a PLC assignment of zero until June 1st of the following the year in which a PLC is assigned.
Load Profiling Issues
25.	Q.	What load profile classifications are used in the Ameren Illinois service territories?
	A.	For information on the load profile classifications, please see Ameren’s Load Profile Classifications web page.
Meter Data Management Agent (MDMA) Issues
26.	Q.	If a RES elects to have multiple Commercial Pricing Nodes (CPNodes) in the AMIL control area, how will Ameren determine which load should be assigned to a given CPNode?
	A.	Ameren allows a RES to designate default CPNodes. Only one default CPNode may be assigned per each Ameren Illinois company. To designate default CPNodes, please contact the Transmission Services Business Center at 888.263.7361.
Distribution Losses and Transmission Losses
27.	Q.	What dynamic loss formulas will be used for calculating distribution loss factors beginning in 2007?
	A.	The following dynamic loss formulas will be used for calculating distribution loss factors beginning in 2007: Secondary Delivery Voltage: 1.06102 + ((2.1951 * 10^-10)*(System Load^2))     Primary Delivery Voltage: 1.02370 + ((2.4522 * 10^-10)*(System Load^2))          High Delivery Voltage: 1.00816 + ((1.0086 * 10^-10)*(System Load^2)) In these formulas, System Load represents the load for the Ameren Illinois service territories – which include AmerenCIPS, AmerenCIPS-ME, AmerenCILCO, and AmerenIP.
28.	Q.	How are transmission losses calculated?
	A.	Since the start of the MISO "Day 2" market on April 1, 2005, transmission losses have been calculated dynamically. By “dynamically”, we mean that they change each hour depending on the load in, and the flows through, each Control Area. Through the end of November 2006, transmission losses were calculated separately for each of the three Ameren Control Areas (AMRN, CILC, and IP). However, since Ameren reconfigured its Control Areas, MISO changed the way that transmission losses are calculated. During a brief transition period from December 1, 2006 through February 28, 2007, MISO calculated transmission losses separately for each of the four Ameren companies (UE, CIPS, CILCO and IP). Then, beginning March 1, 2007, MISO began calculating transmission losses for the Ameren-MO (AMMO) control area and for the Ameren-IL (AMIL) control area. For more information on how transmission losses are calculated, please contact MISO.
Tariff Issues
29.	Q.	Which Tariffs have components that change, what changes and when do they change?
	A.	Riders TS, PER, HSS, RTP, RMC and CRM all contain items that change at various times. Detailed information can be found in a Summary and Table.
30.	Q.	What is the difference between supply voltage, delivery voltage, and meter voltage?
	A.	Supply voltage is the voltage of the feeder line from which a service point is supplied. Delivery voltage is the voltage at the point of connection between the utility’s facilities and the customer’s facilities. Meter voltage is the voltage at the point where the meter is connected. If the supply voltage and the delivery voltage are different, then the customer’s account is billed a transformation charge. This charge is described in the applicable Delivery Services tariffs. If the meter voltage and delivery voltage are different, then the service point’s metered usage is adjusted before applying any applicable delivery or power supply rates. The most common reason for the meter voltage and the delivery voltage being different is that the meter is installed at a location of convenience. For example, assume that a customer’s service point is served at 12kV (primary voltage). However, the utility owned transformer that takes the voltage from 34kv (high voltage) to 12kv (primary voltage) is located inside the customer's security area. For the convenience of reading the meter, the meter may be located on the high side of the transformer that is outside of the security area. In this scenario, the service point would have a delivery voltage classified as primary voltage and a meter voltage classified as high voltage. Since delivery services rates are dependent on a service point’s delivery voltage, the usage readings taken from the meter (which is at high voltage in this scenario) must be adjusted before calculating billing charges.
Transmission Billing Issues
31.	Q.	Why are the Schedule 9 and Schedule 26 rates increasing effective June 1, 2009?
	A.	For a detailed explanation, please read this document. The current rates for both of these Schedules are posted to the MISO website. Please see the Schedule 9 rate and the Schedule 26 rate.